UPDATE ON THE UPDATE: After much drama and a month plus of messing around (4 visits to get this done and about 10 days without the G2) the new window is in and the motor/cable for the slider replaced (short version on this: They didn't follow the directions on reattaching the cable to the new slider slots and ended up trashing the original motor and cable - so they had to order a new motor/cable assembly and try again).UPDATE: Full rear window replaced which does solve the rear bottom seal for the center slider but the usual sloppy job by the glass company my dealer uses. They also hooked up the slider cables out of sequence which caused them to bind up and wreck the cable spool. Going back Monday for that but the motor/cable assembly is cheap if you had to do it out of warranty (about $120).
When reconnecting the cables to the slider, it has to be cycled to full close before connecting. Noted in the service data but I guarantee either the dealer's techs or the glass techs had no idea and messed it up.
Another reason ALL non-warranty work is handled by ME to make sure things are done right.
Once the new window was in, I did what I hope if the final dry out under the rear carpet until my F-150 Lightning is available mid-2022.
Second time was a charm I guess. The usual carnage: broken clips, glass; even broke off the hex head to the screw for my Extang tonneau rail bracket by over torquing it.
I'm 90% sure the window will not leak as the gasket failure was obvious but the seams are still a question TBD later. If any semi-skilled DIYer doesn't think you should do your own maintenance and basic non-warranty repairs, think again as most Honda service depts will prove you are better off doing the work at home.