At the end of the day, there's a very real possibility that the Rockets strike out on all leads and wind up not signing a significant free agent. That means LeBron would stay in Miami with the rest of the Big 3, Melo returns to New York or heads to Chicago, Lowry stays across the border with Toronto and all those other guys find homes that aren't Houston.
If that's the case, it may seem disappointing at first, but the Rockets are still in good shape.
The Omer Asik trade may have been in vein, and it could actually come back to haunt them considering he now plays for a division rival in one of the best emerging frontcourts in the league. However, the Houston core is still among the best in the NBA in that scenario. That is, assuming Houston brings back Parsons, which they obviously would.
There's a solid chance that the Rockets can sign some other free agent and still bring back Parsons anyway, but Parsons is a hot commodity. Many teams are in pursuit of the former Gator's services, among them the Mavericks, Lakers, Bulls and Suns according to Adrian Wojnarowski, ESPN's Jeff Goodman and Marc Stein (h/t RealGM).
The athletic swingman became a restricted free agent after the Rockets didn't pick up his team option in a strategic move. Because of the restrictions, the Rockets can choose to bring Parsons back if he signs any offer sheet, and they will have 72 hours to decide.
Chances are some team signs Parsons to a very pricy deal that will hurt Les Alexander's wallet quite a bit, but most likely Parsons will be in a Rocket uniform next season. It would take a lot of money to convince Morey to let him walk, but it is a slim possibility.
We've seen the same thing happen with Omer Asik and Jeremy Lin two offseasons ago when Morey utilized the poison pill contracts (the same ones that are hurting the Rockets' cap space right this very moment) to get both of them to Houston.
I don't think Parsons will end up on any team other than the Rockets next season, but he seems fairly intent on exploring his options nonetheless.
Best case scenario is that the Rockets sign either Melo or Lowry (or long-shot LeBron) and retain Parsons. At the very least, however, the Rockets should be able to bring Parsons back and start the process of reaching the Finals over again in October.