Well, after a bit of a fright while powering up the 'new' Frankenstein, all's well. And as I move data from this PC, so far so good. Moving this PC to a media machine seems wise as I type this looking at the TV screen
tl;dr: If you already have a Ryzen 3k, don't bother upgrading. If you were planning on getting an X chip that has an XT alternative, get the XT variant instead--it's the same price and has higher clockspeed. Otherwise get a 3600 unless you were already planning on getting a 3950X which still sits at the top of the stack.
Rumors are that the 4k series may be delayed, but so far AMD is still saying "Late 2020" so right now those are probably just rumors.