The practice for OSX apps is to put the "Check for Updates" on the app menu, and not in the help menu.
We probably can keep the help option around, for those users familiar with monoDevelop, but we should also add it to the main MonoDevelop menu.
This was implemneted a while ago.
Fixed in version 126.96.36.19935 (cycle8)
Author: Eric Maupin
Commit: 6fa010ad906c0560735ba76deb36b4a39b546706 (xamarin/ios-sim-sharp)
Included in Commit: 7aef028bb648590c60ad1c6d09183bb79c84d591 (mono/monodevelop)