Hello,
I've also had a Passat Variant TDI for a long time, and I experienced the same problem with the original summer tires (PIRELLI). The outside of the tires are completely worn, but there's still about 4 mm of tread left in the center.
At ATU, they immediately tried to sell me a wheel alignment check, but I decided not to go for it.
1. because, in my opinion, it's not worth it.
2. because I don't believe it, as my excellent MICHELIN winter tires don't have that appearance!
Regarding the TÜV (German technical inspection), I've replaced my Firestone tires (which had about 60,000 kilometers on them) and switched to Dunlop tires. Let's see if I encounter any problems with them. In any case, I'll be checking them more frequently and not just right before the inspection deadline.
All four of my tires were affected, although that could also be because I regularly rotate them. My independent mechanic said that this type of wear pattern on the front axle is perfectly normal and has nothing to do with the alignment.
Well, in the near future, I probably won't gain any new insights anyway, so I'll just finish using my winter tires for now and hope that I can reach the 100,000 km milestone in terms of durability

.