Why not? If the service is fully decentralized and e2e enceyptwe with metadata included how is this not fully private?
I suppose someone with access to the network could see were the traffic is going to and from, in that case add a trusted vpn + tor. Ok sure it is possible for tor to be tracked and it is possible for a team to hijack your vpn providers servers forecefully and take logs. So technically possible. But even then they will only find who you are talking to, not what you are saying.
But it is also much easier to use countless tracking techiques to locate you, find were you are going and find who you are talking to.
Both of these are very unlikely to happen unless you are being personally targeted by govenment agencies.