ATC aren’t into change for changes sake, they won’t revise the range every year or so just to refresh its profile in the market, indeed even when they give something a major overhaul as is the case here the appearance remains much the same.
The only external difference between the new CDA2 and its predecessor is the arrival of a USB socket where there used to be two more SPDIF inptus on the back panel, but inside nearly everything has been overhauled, and you can hear it.
It’s an odd product though, how many other CD player/DAC/preamps are there on the market, there are plenty of DAC preamps but the notion is that people have stopped buying CD players. Presumably ATC’s market still wants them or it has figured out that with the supply drying up they can meet the demand that exists. And lets face it, we all have plenty of CDs that should be played and quite large segments of the worldwide audio market have yet to adopt streaming. The disc drive mechanism on the CDA2 Mk2 is from TEAC who are pretty well the only supplier of CD specific transports on the market, I must admit that it didn’t get a lot of use in my system but proved itself to be a useful source for instant access to unripped discs.