You might be right. I think I moved after reading this post from the lemmy.world team. Specifically the part:

As the Lemmyverse grows and instances get big, precautions may happen. We will keep monitoring the situation closely, and if in the future we deem it safe, we would gladly reallow these communities.

The fediverse being in a state of fairly continuous growth, ‘as it gets big’ can refer to any arbitrary point in time over the past couple of years or moving forward. The statement is essentially, we will arbitrate the content on the instance for reasons. That’s fine, but not something I personally want out of my instance, so I left. sh.itjust.works was the other instance I considered moving to at the time, and I’d be against the team there defederating politicised instances in the same way. If I were a user there, I’d leave.

It wouldn’t really affect me anyway in this case, I got permabanned from lemmygrad.ml (which seems to share banlists with hexbear) for reason “liberal” after pointing out suggestions Trudeau literally voiced support for nazis were being deliberately facetious.