I played a lot of Diablo seasons. I have always enjoyed them. But there are structures in the Diablo 4 gameplay loop that need to be reexamined to get the more casual crowd on board with seasonal play.
-I know they have mentioned xp boosts, but I think 1-50 in particular needs to be boosted exponentially. It is so much slower and grindier than 3, I don't know how you capture that feel with the leveling as slow as it is. Right now the leveling speed feels more like an mmo. If it's roughly the same in seasons that is gonna turn a lot of people off.
-Renown has got to go entirely. It is the most painful grind I have ever encountered in an arpg, largely because it doesn't feel rewarding at all. I have been chomping at the bit for D4 seasonal play since before the game came out and I am considering sitting them out until it's gone. At the very least, we need more mechanics to earn it organically through endgame activity - like do a seasonal helltide in a region, get rep for that region. Something like that. I have done more than half of the sidequests in the game, the rewards are almost always a joke and even the best ones are not worth doing twice. I have poured hours and hours into renown grinding on my Eternal character and I am still not close to finished. If they're not able to change course on this for the first season or two, then I am among those who would prefer to have the battle pass content on the Eternal realm. I'm just not going to do it again - at best I'll run the seasonal content and try to ignore the points, but those points are huge and that's gonna grate.
-No open world travel to nightmare dungeons. Sounds like this fix will be in before the first season, which is great.
I think if they want to get people excited, they should get a preview out describing some of the perks of seasonal play. Talk about the leveling speed, the mechanics, show off some new items...anything to get people eager to hop in. They have been hyping up how meaty it's gonna be for ages, time to dangle the carrot.