V-cache adds to power consumption and cost and negatively affects core clocks. 5800X3D shines at 1080p. Not much else to justify doing it again on a new architecture already with cache improvements.
AMD themselves basically admitted V-cache only made sense on the 8 core 5800X in an interview, and they would consider doing it to more if the demand was there, whatever that meant, since AMD would know before anyone before announcing it if the performance was worth it in their testing. They def avoided confirming AM5 would last as long as AM4 when asked.
"There aren't many games that get much more uplift out of an 8 core processor and the 5800 is really like the ideal gaming processor of all of them."
AMD's Gaming Chief, Frank Azor, talked about the next-generation Ryzen 'Zen 3 / Zen 4' CPU & Radeon GPU products coming to the market in 2022.
wccftech.com
Personally I think AMD blew their load on V-cache with the 5800X and it wouldn't add much more performance to games going forward compared to what we've already seen. I mean, come on. AMD 96MB L3 vs Intel 30MB L3 and it's only how much faster???