surpisingly: yes, mostly since reorganizing its direct messaging feature to rely on Facebook Messenger, which it self had incorporated the E2EE protocol from Signal, not long after doing the same with WhatsApp.
Though "E2E" is very relative - technically such scheme can only be trusted as much as said end-points - which is hard given than none of the Apps by Meta are open source.
And all these apps have a few extremely glaring holes:
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