MVS local printing under VM/370

I admit, I am puzzled over MVS local printing under VM/370. DOS/VS printing, (CLASS=A,DISP=D), goes to VM/370 local (/io) print. Why doesn’t MVS’s (MSGCLASS=A)? There must be a logical reason…but I don’t see it. MVS’s print just disappears. It bothers me that I don’t see the reason. I assume it has something to do with the USER DIRECT file. Without VM/370 each OS’s print goes to their local directory.