You'd have to be truly ignorant to not know that it was going to happen (not saying that you are). It'll be interesting to see if there any legal recourse, but I'm guessing not.

All of these companies are hemmoraging money to train and provide LLMs. The only option is to charge more. This current increase, IMO, is an alpha test for future increases. Unless there is a major jump in the technology, moreso the logic to train LLMs more efficiently, the cost has to keep going up to stay solvent for most of these major players.