Not all MM cartridges have a user replaceable stylus. My Grado Sonata does not and neither do the upper end cartridges from them.
Grado is NOT an MM cartridge, it’s MI/IM.
Most of them, except for a few models have user replaceable stylus, I have several Grado cartridges, the signature model from Joe Grado is XTZ (this is the best model from Grado, top of the line cartridge designed by Joe) and the stylus is user replaceable!
Do not try to flip the situation, nearly all MM and MI cartridges have user replaceable stylus and they are mid or high output, this is a benefit of MM and MI for decades.
Except maybe for new SoundSmith, a few new Grado models and some new ClearAudio nonsense (which is actually Audio-Technica cartridge body made in Japan for ClearAudio).
Based of the fact that some old Ortofon MOVING COIL, old Sony Moving Coil and old AT Moving Coil have USER REPLACEABLE STYLI, BEING MC CARTRIDGES, I can’t say that Moving Coil have user replaceable styli ! Those carts are exceptions.
So don’t try to do the same for MM or MI, except for a few few models, those type of cartridges are internationally-renowned because of the user replaceable styli, this is why life is easier with MM and MI compared to MC.
The OP is talking about basic Ortofon design and asking about basics.
MM and MI = user replacaeble stylus.
MC = re-tip, factory rebuild or new cartridge.