Just for reference (since I don't know your travel details), we're staying on property and arriving mid June. I made our reservation through a Disney TA last September but didn't link it to my
MDE account until mid-March. Shortly after I linked it I received the mailer pictured in the original post of this thread. I don't know if it was the registration that triggered that or just coincidence as we were at about 3 months out from our arrival date at that point. I received the FP+ mailer at about 70 days out (10 days before I could make those reservations). The final paperwork (coupons, luggage tags, etc) arrived last week at about the 21 day mark but I know those came directly from my TA and she purposely mailed them on the weekend so they would arrive on a week day. I never received a magnet or a flash drive -- our "important dates" were listed on the back cover of the original mailer. Hope that helps!