If they were going to do it, I can't imagine why they wouldn't have done it during the Clinton magazine ban. One of the big advantages of Glock is having a gun with a double column magazine contained within a grip that is thinner than many single column guns.
GeorgeH has compared the difference between making pocket pistols and full-size pistols to the difference between making a watch and a clock. It isn't just a question of downsizing. Most of the true pocket guns made by makers of full-size guns aren't worth much, with the exception of the Kel-Tec P-32. Most of the really good pocket guns are made by manufacturers whose entire product line is within this niche, like Rohrbaugh, North American Arms, and Seecamp.
I really like my Glock 26, and will someday get a Glock 19 and/or 32 to go with it. I'd love to see them come out with a true pocket gun. However, I am not counting on it.