Most (all?) open source licenses allow you to sell hosted clusters. They offered a hosted solution well before they changed its license. You can also fork it; but depending on the license, you might need to open-source any fork.
: I don't know of any open source license ones that don't allow someone to sell hosted cluster. Even AGPL, which is copyleft, allows it; so long as the hosted version is either: the same as the open-source version, or it's version is also open-sourced.
Nobody knows what the AGPL actually says, since it has not been determined sufficiently in court (at least in the EU) which is why the license is blacklisted by most companies.
If you want corporate adoption except AWS, you still cannot use AGPL.
I feel like there should be a license that doesn’t allow hyperscalers alone to fork without releasing source while being palatable to smaller companies
: I don't know of any open source license ones that don't allow someone to sell hosted cluster. Even AGPL, which is copyleft, allows it; so long as the hosted version is either: the same as the open-source version, or it's version is also open-sourced.