From some members, yes. But I’m not convinced that’s the norm. I installed my current pair of cats mid-season 2018, and I’m now likely around 18,000 hours on at least one of them (the B3 version), with no real noticeable difference in performance from last year. It’s possible the special new coating may be to thank for this, I’m not sure, but I do suspect I’ll be using it past the 20,000 hours mark.
I also think at least some people are fooled by the hyper-reactive nature of a brand new cat, when describing their noticed difference in performance, upon replacement. Compare year three to year two, not year three to week 1 on a fresh cat.
Highbeam has legit evidence of a change in performance at 12-14k hours, so I do believe he has reason to replace that often. But that may be unique to his setup and usage profile, I’m certainly not seeing anything remotely similar to him.
It would be interesting to see the median age of cats sent in on claims against BK’s warranty on cats.