I believe there was talk of opening it up to the fediverse but not sure where they landed on it

Edit: From the linked FAQ actually

Does Revolt have federation

As of right now, Revolt does not feature any federation and it is not in our feature roadmap.

However, this does not necessarily mean federation is off the table, possible avenues are:

• Implement our own federation protocol
• Implement a promising up and coming federation protocol, polyproto
• Implement the Matrix protocol (unlikely, obtuse and unstable)
• Implement the XMPP protocol (battle-tested and stable)

Any federation that is implemented MUST exercise caution in:

• Preventing spam and abuse: moderators should be able to block malicious actors
• Protecting user data: users should be able to redact all of their information and messages