I'm purely speculating here, but if true, it does make a lot of sense of the rumored timelines. With Raptor Lake 4Q2022 and Arrow Lake 4Q2023, that left a measly 12 months for both Raptor Lake and Meteor Lake to be around. That was quite a short lifetime for those chips. Meaning that Intel might be doing parallel plans for backup. Meteor Lake and Arrow Lake might be two forks of similar products. If Intel 4 yield is low, or if Redwood Cove/Crestmont does not perform well, then Meteor Lake would be a niche smaller-area mobile product until Arrow Lake can take over. Alternatively if TSMC N3 (which is currently in at-risk production) struggles, then Intel has Meteor Lake available to ramp up as they get more EUV instruments.
The lack of definition about the number of E-cores in Meteor Lake is also interesting. If Intel 4 yield is low, then having only 16 E cores will be easier to produce but wouldn't be very exciting as a multithreaded desktop chip in 2023. But if yield is high, then they could go up to 24 E cores.
Essentially, is this Intel's way of preventing another delay like they had with 10 nm?