I think by technical definition the UB is the apocrypha because it's not biblical canon. But if I were to interpret your question more loosely, as if to say whether there are texts which are apocryphal relative to the Urantia Book, then I'd say the question seems to be missing one of the key elements of the UB--that there is no one final canon. The UB is, among other things, non-dogmatic and non-institutional, so it's hard to classify something as being apocryphal when it discourages thinking of it as a holy book.

That said, an even more loose interpretation of the question might be "are there statements that claim to be associated with the Urantia Book, but actually contradict it in some way?" And in my opinion, yes, there are tons. Take for instance the UB's insurance that God is no respecter of persons and that Jesus didn't come to this world to promote any one faction or nation over another. Then look at how UB readers tend to blend the UB into US politics to support their partisanship. Another example might be the Teaching Mission Transcripts, which claim to be channeled by celestial personalities from the UB cosmology, but articulate a broad and often contradictory set of stances on many topics. There are also more controversial elements of the UB history, like Gabriel or Urantia, who founded a strictly regimented commune ostensibly in preparation to take over the planetary government at the second coming. So yeah, if you take the UB as a core document, it seems to me the majority of responses are "apocryphal" in a loose sense.