There's no way Apple will capitulate on sideloading in the US. It's clear they are going to go every inch as far as the law allows to guarantee their 30%. They will strictly geofence sideloading to the EU, and they may even try to resist even more strongly by challenging DMA enforcement in court as long as they can before complying. And they'll probably pull more shenanigans like this to try to impose the 30% even on third party app stores.