I think with the popularity of something like Game of Thrones which is built entirely on subverting expectations, there absolutely could have been something new and interesting done with Star Wars. If it is executed well, people would surely have bought into it. It really has to be something excellent for it to warrant the big switch though. That's where I feel like things faltered.
In my view, there are two main reasons for why this didn't work in The Last Jedi. Game of Thrones is an original franchise with no ties to other established stories. It is a subversion of genre as a whole, both in the fantasy setting and the manner of storytelling with tropes and conventions. You had moral ambiguity, and real stakes, with characters being threatened by actual danger and even death if the story called for it and the plot was driven forward as a result. People have bought it up in droves and HBO has a colossal hit on their hands. By comparison, Star Wars is probably the single biggest media property ever, and has existed for 40 years. With something that established and that specific, people weren't going to take kindly when you just rewrite the rules of how the force works, as one example, and utilizing something like hyperdrives for weaponry, as another. This was done while trying to pass it off as a continuation of the old stories. These two ideologies don't jive with one another. In reality, they should have just started far away from the Skywalker saga if they wanted to do something different and go by their own playbook. Either make a sequel and follow the established rules, or make your silly reboot or soft remake and leave Luke, Han & Leia well enough alone. Lucasfilm & Disney wanted it both ways.
Second, I would argue that the subversion in this movie exists purely for the sake of trying to be different, but it doesn't actually take anything in bold new directions, away from what we've already seen. In fact, the movie still essentially copies entire story beats from both Empire Strikes Back (Rebels on the run, young jedi training with the mentor, Hoth/Crait) and Return of the Jedi (Throne Room and the lead up to it). It just ends up being a strange mish mash of both, without the connective tissue that makes it stand firm on its own. They hinted at this somewhat with Kylo's dialogue to Rey after killing Snoke, and the possibility of Jedi and Sith both being pointless, so a new path was needed by conforming to neither and fighting for their own new cause, blazing a new trail, much like what they wanted to do with these movies. *This film tries to be so meta, that it hurts my head at times, by the way.* Sadly, in the very next sequence, not 10 minutes afterwards, it's right back to big bad guys blasting the small band of rebels. So, it just ends up coming across as rather pointless. If you're going to take something away that has been tried and proven, it has to be replaced by something in its place that is at least approaching equal or at least compelling enough for me to see how it pans out. Instead, they just killed all of the setups that the previous movie tried to hint at, and wanted a bunch of fresh new payoffs for what was never even suggested to begin with (Leia's powers, Holdo's light speed ram, Broom Boy at the end of the movie, etc. )
There were no little clues or foreshadowing you could pick up on in a rewatch, just a bunch of characters deciding to be incompetent, making poor decisions because that was what the plot demanded. You mentioned the angle of Finn as a storm trooper. I literally forgot all of that because John Boyega may as well have been someone else in this movie. They didn't sprinkle in his past or traits in that respect. How cool would it have been to see Star Wars in a movie from the eyes of a defected Stormtrooper? That would have been a lot more compelling to me than a silly anti-capitalist message on a casino planet.