Half of the mobile 5000 APUs are Zen 2 and half are Zen 3. The Zen 2 chips may or may not be the same as the 4000 series chips with a new code name (it seems likely, but isn't totally clear yet). So far it seems like desktop 5000 series APUs will all be Zen 3, but there's still plenty of time for AMD to make model numbers more confusing before those become available.

The 4650G I got from aliexpress last year is pretty nice though; wish I could have bought it domestically.