Not convinced that's the case. The recent decision, which hasn't been reported in detail looks like it is more procedural than fact based. That is, it's just decided that the original interdict from August is legally sound. It doesn't mean that the new judge agrees it should have been granted, just that it's not so dodgy that he can overturn it. He might agree with it and think it's great though, who knows.
It's not clear what the basis of the original interdict was, simply that parks is "an interested party". Nothing published has shed any light on what that means. There were reports that the courts saw a contract. No reports that they discussed the nature or strength of that contract. No detail on how interested an interested party needs to be.
Whether this is a victory for Rangers depends on why they made the challenge in the first place.
If Rangers will genuinely benefit from Parks presence it is a win.
It's hard to see how they will.
If Rangers launch another procedural challenge it will become obvious that they're simply delaying.
Again, not obvious what the benefit would be. (confirmation bias leads me to believe that it's so they don't have to pay compo and climb down, but other than Rangers being c***s there's little evidence for this.)
Interesting that you see this as Rangers case against the SPFL. My automatic understanding was that it's the other way, but of course it is neither really, it's a two way dispute. Which i hope gets messy and embarrassing for all parties.