No, it wouldn't. Because it would COST THEM money as huge INVESTMENT first.
Let's see: they can make millions on merchandise, free promotion of their film, plus licensing fees, for a ZERO investment.
Or they can spend a few HUNDRED MILLION DOLLARS, and could very well take in a bit more money - but they aren't going to see it in the black for a very long time. Yes, eventually, one could say it would pay for itself - many years later - but when Disney is already taking in so much money from Universal doing nothing, the incentive to take that financial risk seems a lot less attractive while they have a stable of other properties they are investing in at the moment.
Think of it this way - let's say you have a job that pays you $50K/year. You find someone willing to do subcontract the job from you for $30K a year. You get to collect the $20K extra for doing
nothing. Sure, you could make that $50K yourself, but you would have to work full time at the job. It's pretty easy to see why someone would pick the $20K for doing nothing, because then you are completely free to invest your time in other activities that are profitable.
For Disney, that means - they have the extra capital to go into Star Wars, Avaturd, etc. - while still raking in a nice amount of cash from someone else doing all the work for Marvel.
Besides, the mic was already dropped in this conversation:
Given that Martin is easily the person on these boards I have found with the most trustworthy, regular, reliable insider information - that's enough for me.