@forthy42 What will happen in that case is that they will claim they can, unfortunately, not allow your instance to federate with them as your instance does not meet the minimal requirements wrt support for whatever extension they deem necessary.

And as they talk a lot about moderation, they could even g0 as far to say that only instances that pay for their (Metas) moderation work are allowed to federate. Which can be for free if you "just" support their tracking, ad and other extensions.