Yes the road to/from the pet passport area is now 2-way otherwise you couldn't go back to the check-in area once you've sorted out your pets (not one way as it shows on the old view), but it's the bit FROM Cite Europe's road into the PP road that I'm interested in ... I can't see any reason why you can't now go IN though that gate instead of having the 'motorway' tour to get to check-in.
If no one can have a shuftie I'll have to drop ET a line and see what they say ... after all, if we could go in that way it would mean a few more mins in bed!
I would suspect the sliding gate is probably closed at night (it does have razor wire attached to the top) to prevent unauthorised pedestrian access to the check-in area.
If you arrived at the ET check-in at night and decided to abort (for whatever reason), I guess ET staff would open the gate remotely to allow you to exit the check-in area.