The feature isn't "auto crush" at all. It's a feature to make all units auto-scatter when attacked. That's literally all. The equivalent of pressing X whenever it's attacked.
And, indeed, it's just one of these hidden options. Just like wheeled vehicle rotation, and MVC undeploy... and 6 player LAN, and enabling music remixes, and tree targeting, and building helipads without helicopter (which I think is a more useful option to put on cncnet, actually), and showing civilian names, and disabling bibs, and a bunch more