Hello,
Thank you for your feedback. There is nothing to change in the documentation. I am reassigning this ticket to an engineering component for evaluation (please change the component if glibc is incorrect, I am just guessing).
Thanks!
compat-libstdc++-33 was provided as a convenience to developers between RHEL3 and RHEL4. It still ships in RHEL7 Optional, but is very old and unsupported at this time. There are no plans to release this package for RHEL8 for those reasons.
Legacy software can be run in a RHEL7 container on RHEL8.