It seems unlikely to me that corporate instances would ever actually federate in good faith.

They may appear to be compliant initially, but in the long term they just have different goals.

I'm not sure where exactly the line gets drawn, but at the far extreme, I say we treat money-making instances as bad actors. If they stand to gain profit from their actions, they need to be defederated to prevent the sabotaging or enshittification of the fediverse.