The upstream sources no longer have the support for the environmental variables that were used to fix this issue -- actually, the one that was used for this has never been upstream, however upstream decided to drop the support for setting options via environmental variables altogether.
We introduced the new (non-upstream) environmental variable in order to allow people from sgi to transparently add new option to ipmitool that previously did not exist in RHEL 6. This is not of any use in RHEL 7 (it supported the -n option from the beginning) and I believe it is ok to diverge from RHEL 6 in this case -> resetting flags.
Unless anyone has any objections, I believe we can close this one as NOTABUG.