I mean, I can definitely live with it. I just wonder if it's an additional concept that will need to be explained when talking about the fediverse with a more general audience.
I feel like I'd probably be saying "instance, also called server" a lot, same as when I sometimes say "Mastodon and the larger fediverse".
Although, admittedly, I'm relying on personal and other anecdotal experience when I assume that less techy people are familiar with "servers". (Eg. Discord using the term, my own conversations at work with non-developers, etc.)