I can't speak to the current status of KAI, except to say that it is still in business and is still making/selling Kershaw & ZT knives.
Kershaw is seldom mentioned on BF because most of it's knives are "budget" knives which seem to be beneath discussion here but there have been many discussions of ZT on BF. A simple search will reveal them and there is a Kershaw/ZT thread for the fans of the brands.
I'm the owner/collector of over 60 Kershaws & 40 ZTs, all of which are "older" and mostly discontinued models, including 5 variations of the 0452 which obviously is one of my favorite ZT models. It's one of the older models that ZT is still making which I assume is because it is still selling well.
AFAIK, the quality of ZT's current production models has not been raised as an issue.
Most of the recent complaints have been abougt ZT's deviation it's prior tradition of buidling "proudly overbuilt" knives for use by military & law enforcement personnel, starting with the 0100, 0200, 0300, 0400, 0500 & 0560, to lighter & more impractical designs, like the 0707 & 0990, that seemed to focus more on form than function.
However, even when ZT made the effort to return to the older "overbuilt" designs, like the 0308 & 0600, after a couple of years with tinkering w/the more modern designs, the reaction was less than enthusiatic because ZT had already alienated its established customer base to such an extent that they (the customers) had moved on to other brands and because the "newly overbuilt" models really weren't much better than what ZT had produced in the past.
But, I think you will find that older ZT models (which were made to last) are still very popular and collectable knives.
Current production versions of older model likes that they still make, like the 0452 & 0562, are also still very popular & should be available for less than older collectible verions of the same models.
I've seen current versions of the 0452 going for around $125-150 which is a STEAL when you consider it retails for $272 and sells at a discount on AMZN for $213. So, if you have your eye on a 0452, I'd say buy it, especially if you can get it for as little as I've seen them selling for here on the Exchange.
Good luck!
OBTW, here's a pic of my collection of 0452s:
In order from top to bottom they are:
1) 0452CF
2) M390BLU
3) M390GLD
4) 0452TI
5) 0452GL
I also owned a 0452TIBLU (all blue annodized handle) but I didn't like it and sold it long ago.