Hard to know for sure but my read is that the cooler blocks RAM slots as stated.
The warning could actually apply to bot the Dark Rock Pro 4 and the Dark Rock Pro TR4
What you will need to is to get the Motherboard's User Guide/Manual and the applicable Cooler Installation Guide/Manual and read through all of the installation notes including fine print, caveats and warning, etc..
Likely the User Guides/Manuals will refer to the manufacturer's website's for more and updated information.
While at the websites check the Forums and FAQs to determine what other users are saying and asking. Pay attention to what is said as well as what is "not said".
Check physical measurements.
Motherboard User Manual:
https://dlcdnets.asus.com/pub/ASUS/mb/LGA1151/PRIME_Z390-A/E15017_PRIME_Z390-A_UM_V2_WEB.pdf
Verify that I found the correct Motherboard User Manual.
Chapter 2, physically numbered page 2-3 provides only very basic instruction for installing a cooling fan.
Cooler:
https://www.manua.ls/be-quiet/dark-rock-pro-4/manual?p=1
Again verify that I found the correct Manual.
Note the the manual actually contains instructions for three different cooler installation scenarios.
Not helpful either with respect to determing the end fit.
Contact Be-Quiet and get written confirmation one way or another if the cooler will fit to the motherboard without blocking RAM slots.
At least there was a bit of a warning.....