AMD is in a bit of trouble here. They tied Zen 4/AM5 to DDR5, assuming Intel had done the same with ADL and would be subject to the same constraints, and were then blindsided by Intel launching ADL with combined DDR4 and DDR5 support. So now Intel is ahead in terms of product launch, it's much cheaper to upgrade to ADL than it will be to go to Zen 4 because you can reuse your current RAM with the former, and ADL's aggressive pricing against AMD's extortionate pricing and lack of true low-end options is definitely going to swing a fair bit of marketshare back Intel's way before Zen 4 gets out of the gate. In short, AMD is staring down the prospect of half a year or more without any new product launches (no, the stupid 5800X3DOMGWTFLMAOOO doesn't count), against a competitor's refreshed and compelling product stack... not a good place to be in.
The problem IMO is Zen 4 being designed for AM5 and thus coupled to DDR5. When AM4 launched, DDR4 had already been on the market for 2 years, but DDR5 will have had a year or less of market presence at the time that AMD hopes to launch Zen 4/AM5 - and that's before you take into account the DDR5 shortages and price hikes. To my mind it would've been a lot more logical to keep Zen 4 on AM4/DDR4 (which could have been released sooner, perhaps even preempting ADL), then release Zen 5/AM5 as a simple Zen 4 refresh with DDR5 support a year later.
Say what you like about Intel, they've definitely been a lot smarter about the DDR5 transition than AMD has. I'm honestly expecting Zen 4 to slip to 2023 at this point.