The people against this on X are probably not building a business. They wouldn't be giving PlanetScale money anytime soon.
These are potential paying users not freeloaders to evict.
Whether or not these folks on free plans are ever going to convert to paid, they trusted PlanetScale to serve as a critical building block for their project/business. I think the least they could do is ease the transition by offering them a reasonable amount of time to offboard.
I personally would never trust critical infra to a company that has ever abruptly terminated a product offering with only 1 month notice.