Read my post again, I said
FF characters being off limits: That memo to trading card artists specifically stated no use of the FF and related characters,
not the X-Men.
Some X-Men stuff has been cancelled (the diorama thing), and they have been removed from some merch with art that originally included them, but they are still big enough names for Marvel to use them in other media (in their comic form, not any movie based variant) and to make new toys: There's a new line of X-Men toys coming out this year from Hasbro.
The same cannot be said for the Fantastic Four. You can still find old stuff online, but anything new?
More fuel to the FF merch fire:
http://marveltoynews.com/marvel-select-watcher-figure-reissue-cancelled/
The Watcher was on the list in that memo btw.
Bottom line: X-Men merch and games based on the comic versions is still being made, but still nothing based on the movie versions. Fantastic Four merch of any kind it seems remains 'off limits'.