Yes, it does. Although, caveat: Not every one of the distributions listed under [0] does. MMS is difficult though, it still has to be properly implemented in the GNOME-ish software stack that bases on ModemManager instead of Ofono.

Regarding the Librem 5: The final hardware (Evergreen) supports calls and SMS reliably. Unfortunately its battery life is still a bit lackluster.

[0] https://wiki.pine64.org/index.php?title=PinePhone_Software_R...

Yes it does. In some distributions receiving calls was a problem (they slept too deep and woke up too slow).

With Mobian for me it now works stable enough to be used as a daily driver.

Librem 5 didn't have working call audio for something around two weeks since the shipment of the first early batch almost 1.5 years ago. It was enabled with a software update.

Yes, it works but it might need a bit of tinkering. This should probably be fixed soon, hopefully with the day 0 update.