I like this personally, it's an interesting take given that Kishi just rewrote history in the last chapter. It gives a plausible theory as to how Itachi got the MS, while trying to maintain some consistency with the manga history. Thus, I wonder if Shisui knew Madara. This explanation doesn't bother me, right or wrong.
What does bother me, however, is that Itachi said Danzou stole one of Shisui's eyes (in the picture it's the right one). I find that puzzling, given Shisui had the MS (so at least one other doujutsu if he couldn't unlock Susanoo or whatever MS doujutsu he had), had a powerful body flicker (known as Shisui of the body flicker), Danzou didn't have all those Sharingan until after the Uchiha slaughter, etc. Thus, how did he overpower Shisui, ambush him with ROOT, or whatever. Shisui seems way too strong to just go down like that, and if Danzou didn't steal it as Itachi thought, why would Shisui give it to him above all people?
Peace