Always AQ, the Rambam actually does not Pasken like Shmuel. This is obvious in his Psak of not wearing armor on Shabbos as well as how he says that the Neviim are not describing Olam Habaa, so he holds like Rebbi Chanina and not Shmuel.
He merely borrowe Shmuel’s words to express that nature won’t change. But as you likely know, he believed that Nevua may 3ven return before Moshiach arrives.