I believe that Disney wouldn't release Black Widow on Disney plus for now, according to Victoria Alonso, Marvel movies are meant for theatrical release, but when 29th April comes, and theaters are still close, they have no option but to release it on Disney plus and VOD

If it gets to the point that a whole other year goes by and we can't watch it in theatres, then yeah, of course they'll put it on streaming. But, I can almost say for certain that they'll keep it to a theatrical release (as they haven't done it already, so I doubt they'll change that just because DC did it... Although...)

I think the most logical and likely course of action for the movie is to first release it (and if necessary any subsequent movies) on Disney+, then re-release them in theaters when the pandemic is over.

How is that logical? Even if they had people pay for it separately, think about all the money they’re losing. Once you buy the $30 movie (one time) you have it forever, and as many people as you want can view it, all within that one purchase. Then if it was released in theatres afterwards, why would anyone go see it, when they could just rewatch it at home and not have to pay anything, and arguably have a better experience?

Well it seemed like an okay plan to me.