Eh, Sosnik isn't that clever of an analyst.
First of all, it's way too early to say for sure. He's right, though, in that the same factors that helped Trump last time would probably help him again (First, third, fourth points).
His second point about third party interference sounds more like an asspull. It might happen, but there's nothing to indicate at this juncture that it will be more of a factor than the nearly non-factor it was last time.
We don't even know yet who the Democratic nominee is yet, fer cryin' out loud. I'm not even sure if I trust the Dems to have learned their lesson and not fuck up their primary process again.
The Mueller thing isn't going to be the savior you want it to be. You're better off hoping that he pulls out due to health, or due to just being bored of it all.
Don't put all your hopes in one basket. I would advise on contingency plans, like shoring up the base, establishing a solid ground game, getting with the times regarding social media in advertising, and creating an easy to understand, populist platform based on core progressive tenants.
Or, you guys can ignore my advice again.