My prediction for the way Hazbin Hotel is gonna go:
Sense theres only 2 episodes left of season one and the next season is already confirmed i dont think anyone is gonna get redeemed and go to heaven this season, it would feel too rushed.
The leading theory and naritive the show is going with is that Angel Dust will be redeemed but just a few episodes ago he had very little interest and Charlie and Vaggie both said he has put in very little effort.
Sir pentious would be the only option for redemption but i think its more likely he'll die, he has no concrete bonds and if he'd die there would be no arc left open.
Another reason i dont think Angel will go to heaven yet is because they have to 1) address the situation with val and 2) viz said that she wants to explore Huskerdust over several seasons
So, season 1:
From what we've seen the next 2 episodes will be very dramatic and most likely contain the extermination with the Hotel being the nr1 target.
Personally i believe that the season will end with Heaven ending the exterminations because they'll find out exactly what happens and Emily will get it stopped.
Most likely i feel Adam and Lute will be banished (maybe also go to hell and be the villains in s2) and we'll probably find out why Alistor is so invested in the hotel and where he was for 7y.
The season ending with no more exterminating and a deal that if Charlie can prove that a soul can be saved those sinners will be accepted by heaven, which will be the buildup for s2
S2:
Knowing that Heaven will take redeemed soul they have to figure out what it takes to be redeemed (its almost definitely more complicated than Adams list). Well probably have some montages of 'becoming good' and we'll see how a deal/ownership over a soul effects the person and what has to be done to be free of the contract. Because logically if your soul belongs to another demon you can't just fuck off to heaven
This will build Angel and Husks bond and probably end with both of them becoming free of their "owners" (hopefully see Val get a beat down). The main villain like i said will probably be Adam who would try to fight again the sinners going to haven now that he's cast out. Maybe we'll even see Eve
Maybe also exploring more about Charlie and her powers and family dynamics
Building up to s3:
Where idk