Considering TOS novels set during the 5YM are the best selling Trek novels, I doubt Pocket has any regrets about how they've done their TOS novels.I think it's a smart idea to go with an "official" season 5 series. You hook the people who dismiss the books and comics "because they aren't canon" and are still completely free to ignore it when it suits you.
Pocket should have done this 20 years ago.
That theory falls apart when you look at Star Wars. Since the rebranding of the old EU as Legends and the declaration that the new novels are canon, the old EU with the Legends banner signifying they aren't canon still sell just as well as the new canon novels. In fact, the old Thrawn trilogy actually surpasses the sales of the new canon novels.I mean I think slapping a worthless "official" label would boost sales. Telling people that the books and comics are canon would bring in a segment of the audience that would otherwise ignore them because "they aren't real." Does it make sense for people to think that way? No. But, they do. Take their money.