Two hots, one shared neutral, can it work with plug on neutral GFCI/AFCI breakers?
Three separate, but related, issues here:
MWBC
An MWBC must have at a minimum a handle tie for common maintenance shutoff. But the usual thing is to just use a double-breaker. Either one accomplishes two things:

Makes sure that if you turn off one half of the circuit for maintenance, the other half is off too. Otherwise you could end up with some dangerous situations on the shared neutral.
Makes sure that the two circuits are on different poles (i.e., 240V between them). Otherwise you could easily end up with an overloaded neutral.

GFCI
GFCI can be provided effectively at either the breaker panel or at the first device in each chain that needs to be protected. Two combination GFCI/receptacle devices often costs less than a GFCI/double-breaker and has the advantage of putting the GFCI reset button closer to point of use. On the other hand, a GFCI/double-breaker has the big advantage of simplicity. Once you get the breaker installed correctly, everything else is &quot;normal&quot; - no concern about LINE vs. LOAD.
AFCI
Unlike GFCI, AFCI is most useful either as a breaker (in this case, a double-breaker) or as a deadfront installed close to the panel. That is because AFCI protects against problems with receptacles, fixtures and other devices and also protects against wiring problems, so putting AFCI close to the start of the wiring run makes the most sense.
Note that code does not require GFCI or AFCI &quot;everywhere&quot;. But assuming that you are required (or want to do so for any reason), the typical installation would be a GFCI/AFCI double-breaker. However, as far as I can tell, but one of the people who actually really knows this stuff can tell us for sure, Square D does not make QO double-pole AFCI + GFCI breakers. Which means that either you have to give up one of the functions, or get the AFCI protection in a double-breaker and push the GFCI protection to either a deadfront or replace the first receptacle in each of the two halves of the MWBC with a GFCI/receptacle device.