What if they're auto-attacking? Would they stop auto-attacking to make way for you?
If they don't stop auto-attacking, then chances are you'll still get creep blocked anyways. It's the stationary, fighting mob of creeps that block you (I think. Do champions get locked down by minions not in combat?).
If they do stop auto-attacking when you step within 200 range (or any range, I'm guessing), then players won't be able to stand near their own minions at all. Much of laning phase is spent near your own minion wave.