There are two configs of 747-400. One has 38 Club seats and the other has 70. On the former seat 19E is in WT+, on the latter it is a Club seat.
If Manage My Booking is telling you that it is WT+ then it would appear that you are on a 38 Club seat plane.
I was on a similar booking a year or so ago to SFO and it appeared to be a 38 Club seat plane on OLCI - but on the day it was a 70 Club seater - so there were a lot of happy WT+ that day.
See
www.seatexpert.com to see the differences in seatmaps on 747s