This is certainly a growing trend which was first started amongst end-users themselves, and slowly we've seen a few news media outlets also following suite. So far, only a very few government agencies have actually followed. Coming to mind are also The Netherlands. What is attractive for many organisations and agencies on Mastodon, is that...
Such an algorithm has to run server-side, since it needs access to the full database of content.
It would be possible to allow users to upload their own algorithms (for example via Web Assembly), but I don’t know about any service that allows for that.