Yes it is contradictory, but it’s also been like that consistently, ie for quite some years.
It also doesn’t include the Fareham - Eastleigh line so does that mean tough luck if you happen to be on a GWR▸ service that normally goes that way?
Yes
As the map is the definitive statement of lines, it would suggest the ticket is not valid in the Rhubarb Loop train, nor on trains from Westbury to Castle Cary that use the Frome avoided; you might suggest I'm being pedantic in that latter case, but the Weston-super-mare avoider IS shown.