When I had the opportunity to ask Hasbro about this at NYCC several years ago, the Star Wars team would only say, 'No Comment". When I asked Lego, also at NYCC, they remarked that they were not able to address it further (or something like that - I specifically remember the 'no comment' though.)
Now, while Lego has offered polybagged Star Wars figures after 2010, it is important to note that these have been promotional items or store exclusives with later sales to clearance out remaining stock by a vendor. Lego Han Solo in Hoth Gear was a lego incentive and only available for free if $75 or more was purchased through the Lego Store. Rocket Raccoon was aTRU Exclusive that was originally a store promo if $50 or more was purchased in Legos in the store. Eventually, TRU sold the items individually. This brings us to Marvel.
Keep in mind that Hasbro also has the license from Marvel / Disney to produce action figures so the same type of arrangement probably exists on Marvel figures as the Star Wars figures concerning what Lego does.
So while Lego was able to secure the rights to produce and sell individual Simpsons minifigures, it is very unlikely, that unless Disney steps in, that we will see individual Marvel or Star Wars figures sold in the minifigure assortment. This is highly unlikely though, as Disney is starting to have a strained relationship with Lego... but more on that later. (Maybe today actually if I feel like writing more.)
I have that set, still sealed.