The following long article states re Mt.16:28:
"At least six plausible possibilities have been advanced.
- Jesus looked to His resurrection.37
- Jesus meant His ascension.38
- Jesus looked ahead to the Holy Spirit coming at Pentecost.39
- Jesus pointed to a coming in A.D. 70—the preterist view.40
- Jesus referred to the advance of His kingdom through the church.41
- Jesus had the transfiguration in mind.42"
All of those would harmonize with a futurist perspective of the Scriptures. He concludes “based on a review of these four time-text indicators, that Jesus was a futurist in His teachings, and certainly not a preterist.”
A seventh view of Mt.16:28 that has been held by some partial-futurists (i.e. futurists) is that it was conditional:
"The subjunctive mood calls attention to the contingent (i.e., dependent) nature of what is being affirmed. It speaks of the connection which obtains between what is affirmed and that upon which the affirmation depends for its fulfillment…if that upon which a declaration expressed in the subjunctive mood depends, is not unrevisably certain, the declaration itself is revisable and is not certain to occur… if the will of God, then revealed, was not peremptory, then these prophecies were not certain to occur in that generation…It should be noted that the prophecies of the establishment of the kingdom within that present generation of Israelites to whom Christ came, were necessarily provisional. They were contingent upon Israel’s national repentance and acceptance of Jesus as the Messiah and Saviour.
concordant.org/expositions/corre … eneration/
“This indeterminacy may be a bigger issue than it might appear at first. There are several schools of thought that see a “parenthesis” in this period, corresponding to the age of the Church–cf. Rom 11.25, and some that see the entire event-stream as being conditional like the prophecy of Jonah 3.4. There were Jewish groups that also held this conditional nature of the timing of the 2nd Advent. So Keener (BBC:115) summarizes:”
“Jewish teachers struggled with a tension between two positions: (1) one could predict when the Messiah would come, in a time ordained only by God; and (2) one could not predict his coming, but he would come whenever Israel repented and wholly followed God. This is a distinct possibility.” christianthinktank.com/qaim.html