Hoenn wasn't really a rebirth. Some 3rd Gen pokemon premiered in Johto, so they still had ties to each other even though Ash started fresh in Hoenn. But no 5th Gen pokemon have appeared in DP, there wasn't even a mention of Isshu in DP, and it's nowhere near the other regions, further signifying it as a clean slate and a new beginning for the series.
Also, in the games, no Generation V Pokémon are pre evolutions/evolutions of older ones and no old Pokémon appear in BW until you get the National Dex.
Either way, I hope Ash doesn't get all three Starter Pokémon, although it might happen and I guess I'd be fine with it. Pikachu, Mamepato & Mijumaru have already been confirmed to be on Ash's Team. Ash seems to be battling two different Tsutarjas. One against Shooti and one in the wild which is female and probably not Shooti's, so maybe Ash catches it?
There also is a Pokabu shown in the Sanyou Gym (where Mijumaeru VS Yanappu was shown), which might be Ash's as well.
Wildcards for Ash do seem kind of hard to guess right now, so I'll leave that one blank.
For Dento, I think he might have Shikijika along with Yanappu. Yanappu is confirmed to be in his team against Ash and in the games. Shikijika was with a few Pokémon in a poster underneath the main cast. Zekrom, Reshiram, Mijumaru, Pokabu, Tsutarja & Zorua were there for promotional purposes. Mamepato is on Ash's team, Kibago is on Iris's team, but what of Shikijika? Why show Shikijika? Dento is a Grass Type Gym Leader, so maybe he has one. We do know that Dento has two Pokémon when you battle him in the games, with one being Yanappu, which he also has in the anime and I'd assume that he'd have at least two Pokémon in the anime as well.
For Aloe, she probably has two Pokémon in the anime, like in the games. Since she uses Normal Type Pokémon, I think she could have Yorterrie. It seems to fit Aloe and is a Normal Type Pokémon.