Echoing @Vermont Green's post, Bobby Marks on ESPN recently said that Hauser's extension kicks in after this season, and that his 10M salary would actually count for nearly 90M next season if kept on the books between his salary and the luxury tax accruals. 90M!
Sorry, I love Hauser but if that's the case I'd have no problem trading him this offseason to a team like Miami or Sacramento who would probably love a perimeter shooter like him for 10M. If Scheierman can do just half what Hauser does, we're perfectly fine. Tbh even last year in the postseason, outside of the closeout game vs. Miami and a few Finals game Hauser didn't really do much anyways and struggled shooting in the middle rounds too.
Moving Hauser could lower the 500M roster bill next year to around 410M, which is what Phoenix is paying their team this year I believe. I ultimately think they could still keep the rest of the team besides that and just elevate the roles of Scheierman and someone like Walsh.
Ultimately I do think Holiday will get traded, if not this offseason then definitely the next offseason (after the 2026 season). If we need to attach a pick to get it done to dump his salary, they'll be fine doing that. Porzingis seems to love the city and fans and I think he also loves his role here. I could see him being willing to re-sign on a reasonable, cheaper deal with Bird Rights beyond 2026 and being okay as the 3rd/4th option. He's already made a lot of money too, and I think realistically even he knows he's not getting a massive deal elsewhere because of his injury history and concerns. Plus, Horford will likely retire this offseason or next so his money and roster spot are off the books.
As long as we keep Tatum/Brown/White/Porzingis we'll remain a contender for many years to come even beyond 2026. Trade Hauser this summer, deal Holiday the next summer, and in that span Horford will probably retire anyways. The payroll bill next year would still be around 400M but that might be more feasible than 500M especially if they make the ECF/Finals. And the years after that become significantly lower especially when Horford and Holiday are gone.
I posted this a while back, I had a table and graph of what our cap would look like going into 2026. I have to find it manually since it's a pain to search, I think it might have been in the Jaylen max thread or one of the second apron threads, but because of the repeater tax we will be paying higher incremental tax rates for every year we are in the luxury tax and do not get under it to "reset" it. Here are the repeater tax rates:
(click to enlarge)

I'm sure Brad and Co have long ago had a plan for exceeding it, staying in the second apron for x years, then trying to reset it and then getting back into it, and timing it in a way that maximizes our window of contention. It's the kind of thing that can be easily done on a spreadsheet...the challenge is a) identifying how long the true window of contention is, b) which players need to be there all the way through; and c) which ones need to be moved once their cost (including luxury tax) exceeds the value they are bringing to the team, and replaced with players who might not be as good but are a lot cheaper (e.g. Scheierman for Hauser, Queta for Horford, etc). They have to figure out how to dip in and out because it's definitely not feasible to sit at the second apron indefinitely and have a superteam, not just because of the repeater tax implications but the roster building penalties.
So sooner rather than later we will have to say goodbye to some folks we like. But we are in a much better position than other teams in the apron like the Suns, because our assets are (as of right now) mostly fungible, they have value to other teams so we could offload them if needed to manage our cap situation. The worst thing is to get caught with aging stars on expensive, long term deals where they are hard to move or cost precious assets to do so.