Available in LIB version 2017.3.1113, it will be also available in the R1 2018 Release.
If RadMenuItem has command attached and the command's CanExecute method returns false, RadMenuItem will be disabled. In case RadMenuItem is inside RadMenuGroupItem, it is not disabled (the command is not invoked, the problem is just visual). Available in LIB version 2015.3.1019, it will be also available in the 2015 Q3 SP1.
Available with the R3 2016 SP1 release.