The lack of warning should make this illegal, but I don't fancy taking on Oracle's fleet of lawyers to take them to court over it. I imagine there will be lots of people getting unexpected charges for their "always free" instances.

I expect there's some weasel words in the contract, but I would expect consumer protection laws (e.g. in Europe) would ultimately favour Oracle's victim/customer.

Oh, wait… you mean the same company that, for years, installed Oracle Database Encryption enabled by default even though it required an extra license?

The same company that, during routine audits, aggressively billed customers for having that feature enabled, even when those customers pleaded, explained, and proved it was an honest mistake and that the feature had never actually been used?

That company is now being accused of doing something illegal?

That company?