Quoted from Bublehead:
All of the Stern Employees had these cool “BOOM!” Deadpool shirts on, and the #1 asked for and not available to the general public item from their store? Yep, DP Boom! T-shirts. So I don’t know who runs the marketing department at Stern, but they are not so keen on coming up with campaigns that generate buzz and sales leads if they keep missing the boat on what the public wants. We all would have been wearing Stern DP Boom!
When you license a property, that does not mean you get to do anything you want with it.
I can't imagine Stern getting the license from Marvel to print their own Deadpool shirts. Chances are they can give the design team some as a promotion for the product, but I wouldn't expect to see Munsters mugs or anything in the near future from this either.