Here is a video showing disassembly of two different style VCT units/"phasers" - it shows the ML3Z-A (the one with the cover) has a different shape for the lock-out pin and oil passages versus the HL3Z-CD (the one with the external spring exposed). It seems that is not only an appearance change - you can see the failure point of the the HL3Z lock-out pin hole design and how it is revised in the ML3Z part.
From doing a parts look-up for a 2018 Raptor, it lists both HL3Z-CD and ML3Z-A. When doing the same look-up for a 2021 and 2023 Raptor, it only lists ML3Z-A. Given that the newer Raptors (2021+) have not had widespread reporting of VCT cold start rattle, this leads me to speculate that the ML3Z-A *may be less prone to lock-out pin failure and cold start rattle due to a change in the lock-out pin hole design.
*Limited reporting of phaser issues for now on the newer trucks with ML3Z-A could also be attributed to lower engine hours and mileage.