It won’t be a problem until .world starts demanding mutual defederation (i.e. instances federated with .world have to pledge to defederate from instances .world deems problematic)

If they do that, the fediverse will absolutely not take that shit sitting down. Obviously it would depend on what exactly their criteria for problematic is, if they have the audacity to deem things like socialism or anti-Zionism problematic or something really broad like that, I have no doubt that tons of instances not even explicitly on those sides will defederate with .world in protest. People join federated social media specifically because they oppose bullshit like this that regular corporate social media try to pull.