It's worth noting that back in April, it was rumored AMD had
cancelled its planned Zen 3+ refresh, but that was in reference to its desktop CPUs, not its APUs. Then in June, AMD unveiled a new
3D chiplet technology called 3D V-cache, and confirmed it would be applying it to current generation Zen 3 CPUs.
So we know for sure that AMD is planning to launch a new round of Zen 3 CPUs with the added benefit of 3D V-cache, which is claimed to deliver a 15% boost in gaming performance. That being the case, it makes perfect sense why a Zen 3+ refresh for AMD's desktop CPUs would be cancelled. In its place, Zen 3 CPUs outfitted with new 3D V-cache will fill the gap between now (well, soon) and when Zen 4 arrives next year.
Speaking of which, Greymon55 posted a follow-up tweet saying, "AMD's packaging plants in mainland China will complete six new products in the first half of next year."