Just like the rumors leading up to the trade deadline, there's always plenty of fallout after. Here's Grantland's Zach Lowe on the Celtics and Rajon Rondo:
Rondo’s below-market contract expires on the same timetable as [Kevin] Love’s, meaning Rondo too has effectively morphed into an expiring contract. The Celtics put Rondo out there, per several league sources, but they did so quietly and in a targeted fashion, and demanded a very large return.
Any team would be cautious about paying Rondo a max contract after next season, when he’ll be 29 and trying to prove he’s still worth that money on a rebuilding team, after a major knee surgery. But with one deadline passed, it’s possible Boston might be eyeing a middle-ground scenario: Rondo plays very well, but not blow-the-doors-off well, and the two sides agree to a non-max contract after next season.
Both teams can revisit these issues in the summer, and the NBA might be developing into more of a free-agency league than a trade league. The NBA envisioned this transition during the lockout. This is why it talked about “player sharing” and pushed for shorter contracts. It wants to be more like the NFL, where teams can turn things around in a blink. Being under the cap carries other benefits — the ability to absorb extra salary in a trade, renegotiate contracts with current players, and other goodies.