In MARSOC, do they teach both MCMAP and SOCP, or just one?
Because MCMAP is a Marine Corps requirement, acquiring the necessary belts/qualifications is something every Marine must devote time to. Sadly, much of the training done in MARSOC is not formally recognized by the Marine Corps. For example, a MARSOC Marine will go through a 3-5 week shooting package which includes both rifle and pistol quals and a heavy dose of direct action as part of his work up. Even after completing this exhausting period of shooting every day for weeks on end, the Marine is still required to go to the KD range for his annual rifle score. Hand to hand combat is no different. In MARSOC, we must satisfy two masters. Both Marine Corps regulations (doctrine/policies/rules) and SOCOM directives must be adhered to.
As the Marine Corps draws down, competition for promotions becomes fierce. In the past, there was less of an emphasis on MCMAP promotion-wise. I think it was seen as "nice to have", but Marines who lacked the higher belts certainly were not passed over because of it. Such is not the case now as I have heard that a Marine's MCMAP qualification will be briefed directly to the promotion board, and will therefore likely carry much more weight with its members. To answer your question above, Both MCMAP and SOCP are taught at MARSOC. The Commander typically will not force the training upon the individual, but rather it is up to each Marine to seek it out. There are daily "rolling" sessions where those interested can come out and learn. These are in addition to the more formal courses that normally span 1-2 weeks.
To add one caveat concerning the original topic: I do think that MCMAP training is important for the Marine Corps. It provides a "common language", or reference point that all Marines are familiar with, albeit in varying degrees. This is especially important when you bring many different individuals together who all have diverse backgrounds and experience levels. Take any given platoon in the Marine Corps, and look at the martial arts experience of its members. At least one third will have previously studied a particular discipline at some point in their life. You'll have a mixture of guys who took Karate, Tae Kwon Do, Judo or Jiu Jitsu. Some of the other guys might have wrestled in high school, fought Muay Thai, or even boxed traditionally. Others still might have no martial arts experience except what was taught in boot camp. MCMAP brings all of these disciplines together, and unites them on a common front. Taking what the Marine Corps provides and satisfying the MCMAP requirement is the first step. Blending aspects of different disciplines together to make more knowledgeable and capable fighters should be the next. Even though I have my personal preferences when it comes to fighting styles, I will never pass up an opportunity to learn from someone who is skilled in their particular art. To do so would only serve to limit one's potential.