I don't think the DotA 2 model would work for Capcom for SF5, for of a couple of reasons: the platforms they are on would not allow that kind of monetization (Sony might allow a fair bit of it, but I doubt you would see something like the Steam Marketplace on PSN), that and Valve is several steps ahead of everyone else here -- and several leagues beyond Capcom at this point. It would be a massive cultural shift for Capcom, and I don't see it happening. The difference in trust is also massive -- there wouldn't be much trust in whatever Capcom does, and can you blame anyone?
If there was a stripped down F2P release of SF5 it would probably go over as well as BoF6. I think the hybrid F2P/retail approach is the best way to handle it right now, similar to how DoA5U and KI are handling it.
Microsoft and Sony are fulling embracing F2P models, and both have titles in development that will allow microtransactions of the sort, to my knowledge MS already has F2P games out that are pretty generous with what they give you for free as well. This is the time when this is no longer an issue and the DotA 2 model
is possible. You don't need a carbon copy of Steam to get the job done, as LoL got pretty far with the same sort of transactions, and kids are still flocking to buy RIOT spacebucks or whatever.
The cultural shift is already happening. Capcom already has F2P games on the market, as does every other big publisher. F2P isn't something new, it's been here for longer than we like to think. And with the way Capcom is moving now, they could use smaller projects during this console transition before they have an install base to justify RE7 which might not recoup the costs in time for their fiscal year end.
And I disagree that it would go over as well as BoF6. People are mad at BoF6 for the platforms first and foremost, and they wouldn't throw one of their top franchises to the wind like SF5 on some of that shit. Look at how they've even handled SFxTK and SFIV on iOS. TBQH, it's pretty respectable and they've provided a decent amount of content for the particular platform. So even if they take an approach where they bring something like SFV (or whatever their next SF move forward is) to multiple platforms including mobile ones, I don't think they'll skimp out and degrade the core console experience, or they wouldn't bother with one at all.