The packet in the plastic envelope comes about 30-40 days before your arrival. It has your trip vouchers and itinerary. This isn't your magical express packet and the luggage tags are merely pixie dust for your bags, they're not the substitute for the yellow tags. The yellow tags will come in the mail at 21-28 days before arrival. They're in the center of your ME booklet.
We just got our plastic packet today for our 4/30 arrival.