Depends on your goals. My guys continue to do both, up until a week before, last week of a camp is recovery week so they only focus on technique, strategy, and weight maintainence. . A 6-8 week camp can be very monotonous, rigourous training. Mixing it up with a little jits (lets say 2x a week) with very light rolling can help ease some of the normal pre-fight stressors and help weight cuts. However I do isolate who is fighting and who is not fighting during class (partner fighters up with each other), so they know to go easy and "play" so it limits injuries. Now obviously in this case its guys fighting Muay Thai, but they continue with training a bit of Jiu Jitsu. Its the same when we have Jiu Jitsu tournies coming up and they witll cut back on their MT, but maybe still jump in a thai pad class or bag circuit class to mix it up as well.