Think of it as basically a UI indicator - behind the scenes, even with one clip and you've never touched that button, there's still a track lane, sitting there, minding its own business, holding the clip. I'd argue that it's poor UI having a button change state to indicate you've pressed it once at some stage in your life, but it doesn't really mean anything, so ignore it and don't worry about there being actualised track lanes in existenc; there always were, you just didn't know about it.