That would be a plus. PGA sucked, IMHO. I was so happy when LGA came along. I got really good at fixing pins, not that I enjoyed it.
PGA worked will, and somewhat does still. But as the number of pins has gone up, it has become more of a pain in the ass. I also like how Intel notches their CPU's, so it can only go in one way. With the arrow method, I could swear it was supposed to be in the corner with the lever back in socket A days (
turns out it was). But with AM4 it is the side opposite the lever. At some point, the corners switched.
My friend got a 2700X for free because it had 40 something bent pins on it. Took a little time I'd imagine, but he got it working. I've had good luck with pins, except once (don't assemble computers intoxicated , or skip reading the manual, as the arrow swapping corners bit me), but I prefer LGA as well.
AMD won't do DDR5 on Zen 4 simply because DDR4 has way more market share and it would be easier for consumers to just use their existing DDR4 with a new Zen 4 processor. I don't think either AMD or Intel would go to DDR5 before 2021.
Also as always new DDR5 ram modules would be more expensive than DDR4 and would stifle Zen 4 adoption rates.
I don't see AMD nor Intel going that route at least until 2021.
They could pull an Intel and be like, hey, we'll sell more chipsets by making people buy a new motherboard. Honestly it is probably just the natural move. Plus marketing might love AM5, DDR5, PCIe5, and make a big deal about the number 5. Just look what they did with 7. What would be nice is if they made different IOD's, one for DDR4, one for DDR5. That's an extra cost for AMD though, then they have to hope they produce the right ratio of both types. For those reasons alone it will never happen.