I believe they will put the updated shafts in your vehicle the tsb shows the updated gm part numbers . I just deal with it and if I someday get tired of it I’ll do them myself . But without the tsb covering them more than likely they will try all kinds of other things and charge me so I’m not gonna bother . I bought a Buick verano about 10 years ago and it did the same thing . I found a tsb for it and they changed them and been good ever since . In fact I still have it with 145k on it .
I hear you. My fear is I've been down similar roads with dealers before. A TSB being just a bulletin and not a recall, etc.. doesn't mean they have to throw new parts on the vehicle for me no questions asked.
They could drive my vehicle for 100 miles and not get it to do the wobble at all. When it does it, it does it very noticeably. I just don't want them playing the blame game. It's your tires, it's the transmission, it's just the way the vehicle is, etc..
My only ace in the hole is I just bought it from this large dealer chain a week ago. It just happened to be from their Mazda store and not their chevy dealership, which is a good hour round trip drive for me. I did make an online appt at the Mazda dealer for next week since that's where I bought it, but I may cancel that one and set something up at their Chevy dealer instead.