Let's assume that Microsoft is willing to sell the IP for a reasonable price, and that Platinum (particularly Hideki Kamiya, who's had to take time off for mental health issues) still has any desire to go back to this, both of which are very big "ifs."
I'm still going to say no, largely going off my own suspicions as to how good this game is/could be. I suspect that Scalebound was having consistent trouble meeting deadlines because Platinum was either genuinely struggling to make the game play in a manner that was fun, or struggling to make the game work altogether (even the most recent 2016 trailer looks...very unfinished). Neither of those is a good spot for Sony to be in.
Then you have to start making connections with Platinum, who, from all reports, seem to be nowhere close to finishing the game, and given the need for several employees to take time off due to the stress of the job, are probably not in the best of states currently. Once Platinum is finally reorganized, you need to keep relations positive (something Microsoft apparently had trouble with) and hope that the studio can stay on track for a game like this. Those are by no means easy tasks, and either of those going wrong could significantly delay this game (again) or possibly derail it entirely. Neither of those are good for sales.
Alternatively, you could try to develop the rest of the game internally, or have another studio handle it, but the problem there is that you're starting from the ground up; with none of the work put in by Platinum so far. And at that point you're basically just telling another studio to finish some guy's idea for him, with no real sense of the direction he wanted it to go other than the bare essentials. That's a recipe for disaster.
In short, no. Games that spend a long time in development hell rarely turn out well. Sony would have to pay a ton of money up front for something with a minimal chance at success. Scalebound is far too risky for the reward it could potentially produce.
