Dishonorable? I don't think so. They're the ones trying to trick employees into immoral and illegal obligations. They only have themselves to blame if it blows up in their faces. They played the game and they lost.
If an agreement is unenforceable, it's almost certainly abusive and exploitative in nature. I mean, it actually got to the point that the agreement was overridden by law. Doesn't even make sense to talk about honor in the same context. Would honorable people propose such an agreement?
They're likely banking on that sense of honor to make you hold yourself to obligations they can't legally hold you to.
