Let me put it this way.

My oven has a proofing feature. It wasn't really advertised, it's just there. I like that feature and I use that feature when baking.

If one day my oven manufacturer pushed an update which removed my proofing feature, I'd be upset.

The same could be said for encrypted memory. If you as a computer owner discovered and turned on encrypted memory because you wanted to feel a bit more secure about your hardware getting stolen. You'd probably be upset that on a normal firmware update that feature suddenly went away. Not because the hardware doesn't supported it or didn't support it. Not because AMD's firmware didn't or couldn't support it. But because someone in an AMD product management team said "Woopsie, that's an enterprise feature, we better disable that".

Completely different story if these CPUs never supported that feature. Completely different story if future CPUs didn't have that feature or had it disabled in firmware. Heck, even a different story if with the disable AMD also said "We disabled this because there's an unrecoverable fault in the memory controller which causes memory corruption."

I have to assume the reason wasn't because of a bug in the feature, but rather because management decided the feature wasn't supposed to be there.

I'm not a user of it, so It's not hurting me personally. But if I had read about how Ryzen CPUs support encrypted memory, and had chosen a Ryzen CPU for that reason, I think I'd have a pretty good reason to be upset that the feature I needed from a hardware product I bought suddenly vanished in a firmware update.

Because I think ethics goes further than "bad thing happened to me", I've formed an opinion that this is a pretty shitty move.