My problem is not with inclusivity but with promoting uptake. If you are familiar with the grammar or phonetic sounds or some of the vocab, you are more likely to find that language easier to learn.
Both English and Esperanto share the same problems of universal languages that I mentioned. English does have the advantage of number of speakers but it is a mess of a language for people to have to learn.
Again to reiterate my counter to universal languages, why not learn and potentially help revive your local indigenous languages. In a world where universal translation exits on our phones everybody being able to speak the same language matters less.
Fracturing the space is way more destructive than whatever you mean by destructive moderating, since the moderating will only affect some communities and even within that, some users while defederating will split the user base.