I had a 2000 Polaris triple. At 4400 miles it needed a piston (carb slide broke and took out the ring) and the dealer reused the rings. Fast forward to 7000 miles, seals leaking and dealer again said "rings are fine, just needs upper seals". Replaced seals and ran it to 8200 miles and it still ran great. Compression was starting to drop and rings would have been needed soon.
I would think 6-7K is average before a compression drop, sometimes (as we know) much sooner. If you're going in to do other work do the rings, otherwise just watch the compression and you'll know when it's time.