It's Too Late For Beetlejuice 2

I think it could work but I still don't think it will happen.

The Maitland's are wrapped up, explain them away by having them moved on to another realm. You think they are vital to a sequel, they are not. And although they could de-age them for a sequel it wouldn't justify the cost, they weren't hysterical but charming in a quaint way. But we are happy their story wrapped up pleasantly. Perhaps Lydia goes back to the old house in need of a way to find Beetlejuice for help, well a 5 minute cameo from Barbara wouldn't cost much and it just reminds us these characters cannot leave their house. Couple ways to do it.

Beetlejuice type characters still connect with audiences today, Jack Sparrow, Pennywise, are just a couple recent examples. Lydia is easy to do because Winona is still pretty hot, 10 years from now maybe not so much. So she could be a lead character instead of a cameo.

Your other points really didn't go anywhere. The easiest concept in my opinion would be to have some new supernatural problem, where Beetlejuice's talents are needed. Lydia has not seen him in 30 years and maybe the Maitland's started to fade from her view little by little to the point she cannot see them or any ghosts. Catherine O'hara is still great so they could bring her back. Burton at this point, I don't know, if he wants to great if he gives it to someone else it would make sense.

And anyway, Alec Baldwin would just end up shooting someone on set.

Why are they keep trying to do this?

Michael Keaton's Beetlejuice Sequel Is Better Than His Batman Return

https://screenrant.com/beetlejuice-2-movie-michael-keaton-batman-return-better/

While Michael Keaton's Batman return in The Flash is incredible, his return as Beetlejuice in the belated sequel is even more exciting.

The logical way to approach a sequel would be to set it in a different house, with different dysfunctional humans. No need to include the Maitlands, no need to explain why a couple of ghosts are aging like normal humans, no need to include the notorious Baldwin.

The Maitlands are tied to their house, Beetlejuice goes wherever he is called, and his heavy makeup will disguise Keaton's aging well enough. I mean they could bring Winona Ryder in for a cameo, but better to have a new cast of humans than update the story of the Dietz family.

I think we’re also kind of past the excitement surrounding the comeback of Michael Keaton and Winona Ryder in prominent roles. Birdman (Keaton’s big comeback) was in 2014, and the first season of Stranger Things (Ryder’s comeback) was in 2016, so a Beetlejuice 2 could have worked around that time or 2018 (the 30th anniversary of the original), but now there seems to be no fanfare. Also most of the people who saw the original at the time of its release now have kids who also have kids so it’s too far removed to still be culturally relevant.

Well, everybody already knew that.

It worked for Maverick.