I imagine (someone can correct me here if they DO know) that it would be down to what the SEC decides. Perhaps, similar to how the requirement for reserves was removed for banks in 2020, they could do the same in light of some new 'crisis' that unfolds in the future. I don't know for sure, but I sure as hell don't trust these people to push Bitcoin in the right direction in the long-term.

If they do manage to suck up a large amount of the supply over time, then manipulation will be much easier for them, since most adoption would be of an ETF share rather then the asset itself.

Maybe I'm being too cynical, but that's just how I am nowadays.