Travelling through the Blue Mountains and the Megalong Valley

I'm planning on doing a trek through the Megalong Valley and other areas of the Blue Mountains, and have bought all the required topo maps. I have a question however, on the gates that I see, which are plentiful in number on 4WD access tracks. It seems that there are plenty of really good 4WD roads out there, and it also seems that most of them are not accessible because of gates which are marked "locked". I'll assume this is correct and the reason they're locked is because they're on private land, water board land, electrical authority land, or similar. The other gates, though, are what? Entries into private properties which should be avoided, or is it a case of it's OK to go through as long as you leave the gate as you found it?

For example, I see that the road to the Cox's River camping area has both "locked" gates and unlocked gates marked on it, with the section having the unlocked type being a workaround for the bit which has the locked ones.

I've read up on the "as you found it" rule but as this is the first time I'm considering going through any area with gates in it (I'm still a newbie), I thought I'd ask here first.