I've only been using Wolf since the early 90's so it may not be any big news that there have been no problems with it for me. Some of the ammo I have is from those years and it's OK as far as I can tell.
Not sure what kind of exposure would make it go bad, but I've found live Wolf 7.62 X 39 rounds on two occasions laying on the ground where I shoot that had been there for some time (probably during winter and summer weather). The poly coating had light surface rust on the side that touched the dirt but they were otherwise intact and looked good except for the dirt on them.
Curiosity got to me and I cleaned them up so as to not be a problem when chambering, then fired them in the Chikom SKS and AK I had with me at the two occasions. Both fired accurately and there were no problems with feeding or extraction.
I don't normally do this kind of experiment but wanted to see if Wolf ammo was durable after such exposure. This could have been a problem with non-Kommie weapons but little seems to affect SKS's and AK's. (Flame shield on).