Installing RedHat 7.3 on HP DL380 G9

I have a kickstart server. I can install RedHat 7.1 and 7.2 on these servers all day long.
However I cannot install RedHat 7.3. I can install RedHat 7.3 on HP DL380 G7's and G8's.
(Also Lenovo's and Dell's). I noticed it was crashing on microcode_ctl.
So I added this line in my kickstart.cfg

%packages
..stuff...
 # Do not install microcode_ctl
-microcode_ctl
..stuff...
%end

This works. I can install 7.3 on these servers now. The question is, how important is microcode_ctl?
Does this voids any RedHat warranty not running this?