Normatively in this blog, such a blog post is made in fully developed explanatory paragraphs, but the deeper this topic is studied out, the more layers and levels of corroborating and furthering understandings are seen. So merely for the sake of, at least for now, time, i.e., the time needed for the full exposition of those studies, this post will here only be made in bullet type “thetical” points, under their pertinent sections, succinctly/conclusorily summarizing these studies/observations. So for now, this is a sort of “expanded outline” of this study. (The citing/linking of source references may also be omitted).
-J.N. Andrews, using a strict chronology, associated this transpired event as taking place when the Seventh Angel had sounded his trumpet (Rev 11:15), however as the organizational structure chart of the book/prophecies of Revelation reveals (see in this post), that strict chronological flow could be broken up here to jump to the start of another sequence of Major visions in Revelation, namely the one dealing with the pivotal final evangelistic work to be done on the earth. (= Rev 11:19-14:20).
-This Third Mighty Angel is also the one whose work and message will “select the wheat from the tares [Matt 13:24-30|COL 74.3-75.1], and seal, or bind, the wheat for the heavenly garner” (EW 118.1; cf. 88.3), which, as revealed to EGW, manifestly by this association with the Ezek 9 message, is to have a distinct Sabbath Truth Sealing application, first in the SDA Church (i.e., COL 70.2ff vs. Matt 13:36-42 (Matt 13:43 = Dan 12:3). Indeed Jesus’ statement in the Matt 13:36-42 parable has left the possibility for such a ‘pre-utter end fulfillment’ by saying that ‘the harvest of this wheat is at the end of this age’ (Matt 13:39 - Greek: aion = Strongs #165, which is not the same notion as the term “world” (KJV/NKJV) - Gr. kosmos = #2889; cf. use in Matt 13:38). And in the present Eschatological Era, the ‘end of the current “age”’ is the end of this pre-Jubilee Era (=EW 286.1); with that then ensuing Jubilee era being a temporal, non-definite, quasi-Millennium Era which the Church Triumphant will usher in, and enjoy.
-This Third Angel is indeed: ‘leading out and purifying a people’, -a “12,000 Remnant of the Judah Tribe Remnant”, all based on actual/proper Biblical unity.’ (TM 488.2; cf. 1SM 175.1)
-Later on, EGW having realized the great authority that is conferred to that Sealing Third Mighty Angel, (which she then also (rightly) saw to be the “authoritative” Loud Cry Angel of Rev 18:1ff), could not help but think that it this must be Jesus Christ Himself (see 15MR 221.2-222.1). Fact is that, as she had seen in vision before (EW 38.2), Jesus merely commissions that Third Sealing Angel with, here, that Four Winds holding back work. But the Christ-resembling/Christ-like parallels which she noticed, perhaps from an indication in another vision, do indeed apply in that Authoritative, Commissioned Angel. In fact, as discussed here, that is all just like she came to assume that the Angelic apparition of Dan 10:5-6 could only be Jesus, but it actually was not, but indeed a “personage” that was just like Jesus, here Gabriel.
-In all of this ‘“Coming up from the East” of The Third Sealing Mighty Angel Gabriel’, which echoes Christ’s Second Coming specification in Matt 24:27, is seen how this prophetic development will indeed be an interim and typological, ‘Second Coming “Advent”’ when it is made to transpire.
-Incidentally, based on EW 168.1 which showed that: ‘each of the companies of holy angels, had a “tall commanding angel at their head”’, the restraining Great Time of Trouble, and also “tall commanding angel” revealed in EW 272.2 is not necessarily Gabriel as some assume.
And, by the way/relatedly, the striking account in EW 266-269 of what was said in a meeting between Satan and his angels in regards to deceiving SDA’s was evidently uncovered by God because, unlike thoughts, the statements there were audibly said. And so, like the infamous US Government's (domestic) spying capabilities, whatever is audibly said, and thus transmitted in the air can be easily grasped by God’s Spirit, -which would then imply/involve that angels, surely fallen ones, and most probably also unfallen ones, cannot inaudibly communicate with each other, i.e., through (claimed/supposed/beleived): “Extrasensory perception “ESP”” mind-reading.).
And beyond merely God’s most necessary need for the surveillance/monitoring/spying of fallen/sinful man, another necessity for the intrusion into Fallen Man’s inner thoughts would most likely have to do with keeping a most complete, and thus accurate record of each Human, for both judgement reasons (=Dan 7:10b), and in order to be able to most exactly reconstitute man’s spirit, and resulting character, fittingly enough through God’s Holy Spirit, if/when they should die. (=Gen 2:7; Eccl 12:7; cf. Luke 23:46|Matt 27:50|John 19:30b). In other words using common computer/cyber technology notions of our day as an analogical illustration, since Man became liable of worms, viruses and crashing, God decided to hack into Man’s system in order to be able to produce a realtime, exact mirroring and archiving copy of their system, so that in the case of even total crash, their system may be entirely and exactly reconstituted, -some (i.e, the saved, clean of any viruses), and that by downloading this information it into brand new hardware, through God’s cyber network: the Holy Spirit, via “breath”.
 Which, in short, for those who cannot obtain access, expounds on the Biblical view that the 144,000 are a literal number of positions that Jesus has to fulfill towards the establishment of the Church Triumphant and so could have increasingly been fulfilled since ca. 1844 to the present by, in regards to now deceased people, the (God-given) work that they have faithfully done towards advancing the cause of the Church Triumphant. Thus, for a prime/obvious example, EGW would have filled one of those position with moreover her work continuing to help advance this cause today.
 And, in relation to the “wilderness” statement of Jesus in the preceding Matt 24:26, as introductorily stated in the related Project which concretizing the here discussed, Rev 7:1-14:20 “Advent” of this Sealing Angel, it indeed will not be the replacement of the Glorious (‘“East to West” Lightning’) Second Coming of Christ, but will instead be an interim typologically mirroring “Thundering” development during that time of, this latest and third, “Second Coming hindering”, but ‘most gloriously purposeful’, extension (15MR 292.3-4)