Host Matrix integration server and possibly (disable?) identity server
I registered on chat.feneas.org yesterday and noticed that it wanted my permission for the New Vector identity and integration servers. I think there is a concern at least on centralization on their services.
I am also under the impression that identity servers don't federate and I consider identity servers as a privacy concern.
There have also been security problems with Matrix.org and associated services that you may have read on their blog. This morning, I saw some talk about other their internal services that somehow are reachable to the public.