Wow, that blew up quickly. Here's my .02:
Not sure why people are reading into this more than what it is. Parker stepped down, Stone stepped in to help, and whether he stays permanently or someone else joins, remains to be seen. It's not really a big deal at this stage. Stone knows the material and has filled in for Parker previously, so to me, it was a no-brainer to have him step in again.
As for Parker's reasons why he left the band -- again, not sure why people wouldn't take it at face value. The pandemic changed the way a LOT of people have viewed life and how they are living it. He's decided to move in a different direction. So congratulations to Parker and thanks for a hell of a good run (12+ years) in the band. Out of all three people that have stood in DeGarmo's shoes, he's the one I felt really made an effort to "get it right" and whose changes to some parts to fit his individual style were done in such a way that they felt seamless. Honestly, I think Queensryche fans should be thanking Parker, not questioning the "whys" behind his departure.
Looking ahead, I think Queensryche continues on the way it has. I don't view their next record as anything different than the one before it, other than wondering if it could be their last. Wilton and Jackson aren't getting younger. As for who writes the record, I'm sure it will be the same as the last few -- La Torre/Jackson/Wilton for the majority, either together or separate, or a combination of two of the three. I wouldn't expect them to rock the apple cart from a stylistic perspective. Queensryche is a business. It has always been, but after the split with Tate, it absolutely is about locking in the fans and the market that support them, and making sure the music falls in the wheelhouse of those fans. I'm sure they will have a track or two that spreads its creative wings a little bit, but other than that, I'd expect 90 percent of the record to be in the same vein as The Verdict and Condition Human. My guess would be that Wilton will do all the guitars on the record, and if he wants a partner, perhaps Stone will do some rhythms. But you really don't need a second guitarist in the studio. I guess we'll see.
Anyway, congrats again to Parker Lundgren. When he joined the band in 2009, I was one of the ones screaming "NEPOTISM!" And it clearly was, at the time. But Parker showed EVERYONE that he is a great guitarist in his own right, did right by DeGarmo's material, did right by the fans, and also developed his songwriting. He EARNED that spot next to Wilton, and I for one really came to appreciate the kind of work he put into his craft. I saw it first hand, pre-show, as he sat in the dressing room playing the set on his guitar to warm up (listening to the songs on his laptop). So if his future is in his guitar business and coffee shops, then good for him. Glad he is happy, and I wish him the best.