I proposed the following question on the elrepo mailing list looking for feedback related to multiple displays changing orientation when you logout (or when X restarts).
http://lists.elrepo.org/pipermail/elrepo/2017-December/003974.html
Based off additional testing we believe this is a driver issue introduced in 375. We’ve tested 375.66 384.90 and 384.98 on RHEL 7.4 and 367.57 384.98 on RHEL 7.3.
At first I thought it was something with Xorg 1.19 however testing with 7.3 and 384.98 it appears it’s not isolated to 1.19 (introduced) in RHEL 7.4.
If you see the above URL you’ll read the key point is whether or not a layout-less xorg.conf (generated by elrepo’s nvidia packages) is expected behavior: Should the layout remain static assuming cabling doesn’t change. This appears to be the case pre-375.xx however I don’t know if this is just luck (really lucky) or something that isn’t expected/supported.