Weather will definitely be the biggest variable for crowds this year, though at least encouragingly there has been some moves this year by clubs (or the NRL) to help grow crowds.
Broncos: The biggest change they've made from 24 - 25 is removing their General Admission areas at Suncorp. Whilst it may seem like a small thing, it is a significant factor between why the Dolphin's biggest crowds at the venue are almost 4K larger. Assuming they have a decent season on the field, hopefully they can at least hold their average.
Bulldogs: The end of the Bundaberg agrees instantly helps the club's average. The club is also only playing 1 game at Belmore in 25, with the other game being taken in Allianz. Assuming the club doesn't regress on the field, a 25K+ average isn't out of the question for them.
Warriors: Reduction of GA will also have a positive effect for the club. With the club expecting to grow membership sales YoY, the club is decently placed to keep their 20K average at home. Assuming they can have a decent season, there is some room for them to actually increase crowds.
Wests Tigers: Best placed out of all clubs for decent growth. Limiting games to Campbelltown, Leichhardt & Tamworth last year pretty meant they were capped out at 17K for their bigger games. Moving 3 games to CommBank & 1 to Allianz allows them to lift their average. Considering the club hosts Easter Monday this year (should be a comfortable 25K+), is part of the Eora Round concept (should be another 20K+ crowd) and also has the Bulldogs at CommBank, their average should increase.
Dolphins: Club has cut its number of Kayo games from 3 to 2, which will give them an instant uplift. Rabbitohs and Dragons are also better drawing teams than Knights and Sea Eagles.
Perth Double Header: Unless PVL says Perth is definitely not getting an NRL team, I'd expect 40K+ for this, which will be a big lift for both the Sharks & Rabbitohs averages.
Eora Round: Assuming the state government still go ahead with their planned promo for the 3 games (Roosters v Bulldogs / Rabbitohs v Eels / Wests Tigers v Sea Eagles) there is a real opportunity for this concept to deliver a combined 75K+.