Hey look, a new 40k post!
Not sure whether anyone here will have any insight but I've noticed that the Munitorum Field Manual 2021 Mk I that came with last month's White Dwarf has some disparities with the Munitorum Field Manual 2021 Mk I downloadable from the Warhammer Community site (dated 04/02/2021). I got the WD one more recently but I have no idea when it was printed.
There aren't many changes but I noticed that the WD one has Inquisitorial Acolytes 1pt cheaper than the PDF which affects two of my armies and several army lists.
I have a feeling that this is the third Munitorum Field Manual 2021 Mk I so far, it makes you wonder why they didn't call the second one Mk II and the most recent one Mk III.
Edit: I sent an email to the 40k rules team but, rather unhelpfully, the automated reply said "While we can’t respond personally, rest assured that your message will be read and taken into consideration when we’re writing the next set of FAQs."