I expect that anyone who really knew Trump well would record any private conversations him, given his propensity for lying. Cohen and Omarosa had dealt with him for years and knew that if he promised or admitted something he might later deny it, so they covered their asses.
So far, however, the tapes she has played for others have proven to be innocuous, mundane chit-chat. None of the new articles I’ve read has suggested that she has anything scandalous on those tapes, but one source said that the tapes can be used to substantiate anything in her book. At this point, we’re not sure if there is anything substantial in that book. The only excerpts I’ve seen so far involve Omarosa’s opinions of the President’s mental fitness, and her statements are so general that they were not even illustrated with examples.