It doesn't stop them from creating Alien or Predator pieces. They just can't sell it without a license. Some of that stuff may be years old and was already laying around the shop.
One of the perks of being in their line of work is that they are capable of producing a piece of anything for themselves if they felt like it. Anyone can do it providing you have the skill set(minus nice things like say...having access to the CGI files of JP in order to create a 1/5 or whatever BO rex for yourself) Most of us don't and is why the collectibles market is jam packed with stuff for us to buy
BTW they never said they aren't ever doing alien/predator, just not anytime soon. If they ever said "never" I would be very surprised at their willingness to leave money on the table. I know what their mission is, but there's not enough stuff in geek culture to last them forever. If you're willing to do Terminator and Robo, you're willing to do A and P :x