Sneaky sneaky Blake custody

Hi gang, a thought occurred to me regarding BTC events over the past 2 months or so:

(I know this is not “original” thinking, but I haven’t seen it spelled out completely yet)

I think it’s very possible exchanges like CB were very aware and planning around the hard fork.
They understood that if they control BTC keys in custody, they also control the new Blake coins.
There is no indication that they will honor the split, ie- they feel entitled to them.

Just before the hard fork, we have rattling coldcard attack, which strongly encourages nervous holders to transfer to exchanges for safety. Bingo, stealth bag pump right before the fork.

Very convenient. Very lucrative for them. Coincidence?

This could all be invalidated if major exchanges start recognizing and crediting BTC holders with corresponding XBT, but why would they?