The fiction is that only those two disciples had that problem. And then RD and club turns around to Acts 1 and says they (all) had the "right" question in 1:6. Or had the right definition of 'basileiu.' Which is it, guys?
The 'people' (ethnei) in Mt 21:43 is not a nation as we know it. It is meant in the same sense as 'man'(-kind) in Eph 2:14 ('hen'). TEV: people. It is also not 'the Gentiles.' It is a new kind of people, whose denominator is faith in the Gospel.
In between when He first called and commissioned the Twelve and just prior to His return back unto the Father; He had invested almost 4 years with them.
And yet, despite all they had experienced and been told while with Him all that time; some of them would end up focused on who was going to sit where with Him in His Kingdom.
THIS is what is behind the question in Acts 1.
Which is why He not only points out once more that it is not for them to know the timing of said Kingdom, but what their focus is to be: given the authority He had given them; and how that the Spirit would be seeing to that: to their being enabled to properly focus on their commission.
They are still scratching their heads, when those two angels once more remind them of what He had told them in Luke 13 - where He expected to find their focus having been, when He returns - giving Israel their meat; in its due season.
And THAT is exactly what they began to do AFTER THAT PARTICULAR Pentecost - "Ye men OF ISRAEL..." Acts 2 thru 7.
In THIS, Acts 10 had been FOR THEM an UNEXPECTED anomaly; thus Peter's sense of "mystery" or sense of a seeming riddle or "enigma" (Paul's understood sense of that in his use of that word, in Rom. 11).
They were thrown off by that Acts 10 event, because both they and the Lord had held that Israel - "the children" - would "be filled first" Mark 7.
Just as the Lord had reminded them near the end of Matthew 10...
But for...The Mystery.
And then you come along with your little red wagon full of books fresh from the nearest library, only to end up thrown off as to the sense of all that, by the lens you approach it all from - from your crystal clear OVER RELIANCE on the notions of men "about" these things...
O, I'm sure your view makes perfect sense to you - from within its vacuum, and all it has failed to consider.
But that is all your view is.
And it is...what it is...at this point - you are - married to it.
Rom. 5:8.