Well the longer they wait the harder it gets to trade him. His 57-million-dollar salary means the c's will almost certainly have to take back at least 2-3 players in any deal to make the money work and the C's already have a full roster of 15 (14 if they cut Banton). The C's are also now right around the tax, which makes taking back MORE money than Brown's salary difficult if their goal is avoiding the tax.
Meanwhile the rest of the league is filling out their rosters in free agency, which is only going to make absorbing a 57 million dollar contract more difficult.
None of this makes it impossible to trade Brown, just a little more difficult than a week ago.
Here's an example: One popular trade idea is Brown+Hauser for Murray+Johnson on the Nuggets. The problem now is that ADDS 5.2 million in salary to the C's. That's 5.2 million they can't easily jettison. So if their goal is "stay under tax" this construction is probably no longer viable.
While true, Johnson is a $23 million expiring contract. Since his salary would not be long-term, it would be easy for the Celtics to remain below the tax next year if they made that deal, even after extending Queta and giving him a raise, and so they could reset the repeater tax then, while still having Jamal Murray to show for the deal.
If we believe getting out of the repeater is somewhat important, then the Celtics just need some of the salary that comes back be expiring. Or a third team gets involved. Or there is a salary stepdown trade at the deadline like last year with Simons for Vooch. None of these things are that hard. Now, if there is a decree that the tax must be avoided no matter what, and before the season starts, that is more difficult. But Brad has successfully gotten under the tax mid season on two occasions now: 2022-2023, and 2025-2026. I do not think this affects much.
The repeater tax inflicts some pain, that is for sure, but it inflicts a lot less pain if you are only $1M-$2M over vs. $20M or $50M over. They have to stay under this season to reset and that will only buy them a few seasons of non-repeater status. I don't see it as the end of the world if they are over the tax but under the first apron for this season. They would remain a repeater but if they are only say $2M or $3M over, it shouldn't break the bank. I know, easy for me to say, but it is what, a $6B franchise?
They are now hard capped at the first apron due to using the full MLE on Robinson. There is about $9M between the tax line and the first apron. If they went right up to the first apron, that would be about $30M in taxes as a repeater, about half that as a non-repeater, so max about a $15M cost for being a repeater vs. not, absolute worst case. I think the franchise can handle that without a major impact on the bottom line. The franchise probably appreciates in value 20X that every year, at least.