MartiusR: Sorry for digging out old thread,but I didn't want to create new one.
I was interested in presence of old Duke Nukem titles on Zoom (DN1, DN2, DN3D and DN: Manhattan Project). And I've decided to e-mail to 3D Realms (told me that I should contact with Gearbox).
So I've sent an e-mail to Gearbox, but didn't receive any clear answer - only "thank you for attention, our team will check it and make further steps, if necessary. Since it was a couple of months ago (in summer, if I remember correctly), and DN games is still on Zoom, I'm guessing that it's legit that those games are there.
Last thing - I've learned from Zoom tech support that they're planning to make "refreshing" in 2019, there will be some big update of their website, as well as new releases and some discounts (at this moment there are no promos on their store). I've also asked, if with this "refreshing" their website, there will be some games removed from catalogue (mentioning Duke Nukem games), but they confirmed, that DN games are staying in their offer.
Therefore, as much as I can tell basing on e-mails I've sent, presence of old DN games in their offer is legit. Which is cool for all those who didn't bought (or added DN 3D in giveaway action) DN games in the past on GOG, before they were removed.
It's is however much appreciated that you go pointing it out to gearbox lawyers that it is still available...