That does seem to be the worry that comes up a lot: Blackrock forcing a hardfork that removes the limit and thereby destroying the most powerful feature of BTC (but thus making Blackrock a lot of money, which is all they would care about). It seems unlikely, because the rest of the community would fight tooth and nail, but then again... if they control enough of it, anything's possible.

Anyway, sounds like an interesting book. I'll add it to my list!