I did some investigation what could be blocking the production of the CDJ 3000... it is using the same DAC as in the CDJ 2000NXS2. The AK4490EQ chip, which was released back in 2014.
Unfortunately, this part became EOL'ed (End-of-live) in June 2021, because a fire destroyed the manufacturer's (AKM - Asahi Kasei Microdevices Corporation) main plant. This means, this part is not available anymore (and never will be again) :-(
The long delivery time now is because PioneerDJ is out of these chips and has to do a re-design of the CDJ 3000 to use another part inside. There is an replacement available, but it has slightly different specifications, which means the PCB needs a redesign which takes time of course.
I wish I would've ordered my CDJ 3000 early this year when it was still available...