Plus HVII pretty much wiped out anyone who had any sort of Yorkist claim & didn't happen to be his missus.
If EV & ROY were murdered, & if they didn't die of a poorly timed lurgy (cf my RIII wouldn't have been stupid enough to kill them before '85 theory) then they were absolutely not unusual in being eliminated as children.
Poor kids. Whatever happened to them, imagine being 12yo Edward V, brought up as the heir to the throne, & suddenly your dad is dead.
You are supposedly in charge of your journey to London, to be crowned,, but it's made very clear you aren't.
Your dour uncle Richard is suddenly in charge of everything.
Your trusted family members are being executed, you're being shuffled off to a nice safe Tower & btw you aren't going to be King anymore, because apparently your parents' marriage is invalid.
& you aren't stupid - you know perfectly well that you & your brother are never going to come out of this prison alive, & you'll never see your mother or your sisters again.
Poor lad. It must have all been completely terrifying.