I think we are all ignoring something obvious here: while not part of the PPGD universe per-say, the Omnitrix does make a cameo in the Vault of GT so that is possible.

You are correct Brandon, but there is a difference between a cameo appearance and becoming an integrate part of story. If they can pull it off, they should do it. All I'm saying, it will be hard to pull it off, without overplaying the character. With the upcoming invasion of the Cluster, the fued between Cluster and Irken, (it would be interesting if the Glorft reappear as well, as a tritagonist in the fued), it could make sense to have Ben on board, maybe as an infiltrator to Irken fleets (as if he appears, he likely will have a DNA of Irken) or mistaken the Glorft for Vilgax (creating a relation between the two species (evolutionary or so). Ben 10 can be a great addition to cast of characters but it can also bring ruin to it.And with the original series, where not everything was explained by aliens, it would be the easiest of the series to make a crossover.

True, But at the same time from what I heard from the Snafu comics forum Ben 10 is one of the series that Bleedman has no interest in adding to his collection of lore. So do I think that it's a part of the overall universe? Yes. Does that mean that I think it will be a part of the overall story-line? No.

Ok thanks @Brandon maybe it's just part of any Fan-based FANON by some fans.

Not being the grammar police but Fanon is always fan-based, hence the name. 

well sorry for not good at ENGLISH.

I have seen worse, far worse but it was just something that I found funny as Fanon literally means Fan-based canon. Fan-based Fanon is a bit like wet water.

ok THANKS for your explanations.

Rook and kevil levin are in the verse this so much confirms ben has gotta be added in it too