Guys, if anyone had followed this guys work at all you would know that literally every fan product this guy has made is part of his "bootleg multiverse." So a cross over between Castlevania and Devil May Cry is about as likely as a crossover with Dredd, or Power Rangers.
Pretty much this, and I've also been telling people who asked my opinion the same thing.
If you're familiar with Shankar you know that 1) he says these kinds of hype-generating one liners all the time knowing full well what he's doing and 2) his "bootleg multiverse" has existed for some years now, in the shape of separate Venom, Dredd, Punisher and Power Rangers "Bootleg Universes".
Visit Shankar's channel. You'll see that Castlevania has belonged on a "Bootleg Universe" of its own for a while. This talk of multiverse isn't exactly news to his persona.
All he truly said is that Devil May Cry is joining his "style" of doing stuff. He just gave it the "Bootleg Multiverse" name.
PS: I would still not rule out a crossover. Shankar likes his fanfiction and is basically Super Waffle with more influence. I'm just saying it's a bit too early to jump to "crossover" conclusions based on a specific wording that Shankar knows exactly what means.