Sometimes we got bugs like bug 659676 Many of the are caused by developer committing an EAPI bump for forgetting to check for some "exotic" USE flag combination that is conditionally calling an old helper that is no longer available. As a consequence, people hit them as a build failure. It would be better if repoman would directly catch the banned/deprecated helpers calls. That affects currently to this commands: https://dev.gentoo.org/~ulm/pms/head/pms.html#x1-122001r3 Thanks
repoman support has been removed per bug 835013. Please file a new bug (or, I suppose, reopen this one) if you feel this check is still applicable to pkgcheck and doesn't already exist.
pkgcheck certainly has BannedEapiCommand.