Any messenger that is open source, decentralised and you can route through darknets is anonymous.

Security comes from encryption, either OMEMO or PGP are gold standards.

Privacy comes from a care of (or lack of care of) stylometry, your OPSEC and what you choose to share over the internet program.

Edit: i wonder who the hell can downvote this non political, non controversial comment devoid of discussing any entity or person, I really got some haters huh