John 7 is an interesting side study on this. This chapter concerns Jesus and the disciples celebrating the Feast of Tabernacles. The Feast of Tabernacles is a seven day event that corresponds to the Exodus, for one thing. I think it also corresponds to the 70 weeks of Daniel, with the arrival of the Second Advent on the last day of that 70th week, which corresponds to the Israelites marching around Jericho also. A lot of things come together on that "great" day:
Jhn 7:37 ¶ In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink.
It makes sense to me for God to have Jesus be born on this great day of the year. People will drink of the living waters at that second advent.
I agree it seems apt. And I think aptness is actually a pretty good argument, but not, of course, a dispositive one.