Rava and Rav Papa argue about the permissibility of pressing dates on the Mo'ed. Why does the Rambam not rule on the dispute?
The BEIS YOSEF (OC 533) raises your question, that the Rambam does not mention this Halachah, but he does not give a reason.
It seems that since everyone agrees that when it comes to a Davar ha'Aved, it is permitted to do Melachah on Chol ha'Mo'ed (as we see that Rava himself permitted Melachah because of a loss, on 11a). They are arguing here regarding a certain type of hard dates. Rava prohibits pressing them because one can wait until after the festival (as the Nimukei Yosef writes), while Rav Papa maintains that if one does not press them now, there will be a loss. Since the matter basically depends upon the nature of each and every species of fruit, the Rambam did not give a decisive ruling but rather relied on his general ruling that a Davar ha'Aved is permitted.
Yosef Ben Arza
YBA:ys