No. Meta is a known bad actor. They have a history of not being good for protocols and communities. They are already guilty. Just not here yet. Preemptive banning is appropriate. There is no reason to give them the benefit of the doubt.

After they roll out their project, then it can be assessed to see how much harm, if any, it will bring. At that point let them in or not, as evidence dictates. It is entirely possible that they will be a good fedi citizen, if the reason for doing this isn't profit. And that is actually possible in this case. Because having some services that use Activity Pub is a way to get get certain regulators off their backs. I wouldn't hold my breath, but it is possible.