This is definitely just the leftover files from BT 3 that they haven't made plans for yet, but are probably thinking about revisiting some of them later. I don't suppose they would start working on those, but then explicitly say "nothing for this season pass", and then reveal the plans that involve Super Hero and Daima who are nowhere in this leak. Seems to me that this datamine is from an earlier planning stage, making this just leftovers.
Now, the more recent Super characters that are just hanging there after Jaco are probably the exception, but I don't know what they'd do with most of them as fighters. Zeno's assistant I assume that's the father of the angels, right ? Who's the Grand Minister ? (or vice versa) I'd sooner assume that these ones will stick to story mode like Supreme Kai right now, although I do expect Supreme Kai to return as playable some time later. Just not Zeno or the Minister and such. Tagoma and Mai maybe someday.
I do hope that Chi Chi would be an adult version and not the kid version though.

Remember when Demon King Piccolo was actually just an alien with magic powers ? Well, Namekians were actually demons all along. You can tell because everyone who has pointed ears are from the demon realm. Yes, that includes the Kaiohs and Shin, who has a brother and a sister. But I think they say it doesn't include Popo for some reason. The Dragon Balls ? Demon realm magic. Demon King Piccolo ? That was just him remembering that he was from the demon realm.
Dabura's sister from Xenoverse was hot so they get more into the demon tribes but without making the actual Xeno guys canon. We do have a tiny guy who watches Dabura getting killed and concludes "well I was next in line to the throne so I'm the Demon King now I guess" in some info dump on Dabura, his dad Abura, and Buu.
So iIt kinda does sound like Demon King Piccolo was in fact a legit demon king like Dabura and the new guy, but I don't think it actually brings that up.

... So there's a shortcut here being made with the "ma" like in daimaoh = demon king but it actually means magic but then it's mostly used to mean evil, so a Kaioh can be from the "ma" world without being evil but most of the people from the demon world are likely evil. Sometimes you'll find that people prefer to translate it as mystic instead (like Makafushigi adventures, OG Dragon Ball main theme, mystical adventures) but it's still most often associated with evil.
Shin's brother and sister are not a kai like him and they're evil.

The bad guy is looking for the "third eye" "crown", which goes on your forehead when you obtain it. So now you're thinking of Tien, but he hasn't showed up so far.

There's been a couple throwaway lines here and there in Super about it, like when I think the Namekian from the Granolah arc says Namekians escaped another world long ago before coming to Namek, and it turns out that was the demon world. And you know how the universe has super Dragon Balls and a giant dragon ? Well, that's all from the Demon world too, which has its own set of (3) balls, and a few others, because that's demon world magic but also heavenly magic from the King Kai people.
There's a lot of stuff that showed up in some compilation books like I think the Daizenshuu and such, that explained the hierarchy of the Otherworld, but mostly talked about King Kai's planet and up. And now we're expanding in the other direction, the demon world, instead of the heavens.

Yeah so the Daima DLC might not just be mini versions of everyone, there's already 2 and a half characters (one is lurking in the back following the new demon king guy, we don't know anything about him yet)

By the way, this happens one year after small Buu died, Trunks is having his 9th birthday... So it's looking more and more like we now have 3 parallel continuities (GT, Super, Daima) and they'll stay separate, since Kibito Shin has undone their fusion here too, retconning Super that already explained it as a wish...
And speaking of GT, it's again contradicted by Daima, because the demon realm has white magic and black magic and the dragon balls are white magic and that's actually the real reason the new demon king can't ask Shenron to kill everyone involved in the death of mini Buu (and instead asks for them to be kids again). So the Dragon Balls being used for selfish reasons too often and turning into black star Dragon Balls becomes self-contradictory. It's white magic.