andyb - I don't know the answer to your question, but thanks for posting this. It reminded me to check the MLBPA's Key Documents page, to see if the 2022-26 CBA had actually become available (it had been about two weeks since I checked)...and it has! I've downloaded the CBA, but I haven't read it yet (it's a 440-page .pdf file).
The answer to your question may be in there (or not - it may be addressed in detail only in the Major League Rules update, and that's not available yet). It may take some time to find it, though!
[Aside: When I read andyb's question, my first reaction was, "Ahh, I'll have to go upstairs to the computer to verify that the CBA is still not available, and then I guess I'll gripe about that again." But no! It feels like it's taken forever, but at last we have the text... which means I have productive work to do.]
[Edit: Based on a first scan of the new CBA, it looks like the details of the draft and follow - and details of any changes to the Rule 4 draft at all - will have to await the release of the 2022 (or 2023, dare we hope) Major League Rules.