Actually, if you wanted to read the regs VERY pedantically, the same actually applies to Part 25 certification ... 25.149 requires that you "establish" 'VMC', 'VMCG' and 'VMCL'; 25.1513 requires that "The minimum control speed VMC determined under Sec. 25.149 must be established as an operating limitation."; and 25.1583 "Operating Limitations" requires that "any other airspeed limitations necessary for safe operation must be furnished".
So we have to calculate Vmcg and Vmcl, but we only have to 'furnish' 'VMC'(a). Of course, having calculated them and used them in the performance calcs, it would seem pointless NOT to publish them.
I believe, also, that 'furnish' doesn't have to mean 'provide a number' - I think one of our types has a statement that Vmca is NEVER limiting, and in fact I don't think a Vmca value was ever determined during certification - it was just shown to be lower than any practical speed. (I'm going from memory, and would have to check to be certain)