I reckon the 97% renewal claim is legitimate. As the lady told me when I was trying to organise a move, the club are sure it's people fearful of missing out on the last game at Goodison. (face it, it's not for the football)
When you factor in pretty much every unsold seat (meaning unsold as a season ticket) has some degree of restricted view, why would anybody give it up a good spec?
Lounges and boxes have dramatically increased capacities at BMD, the club are pushing hard for many to upgrade to some level of membership before a final figure for 'regular' season tickets is decided. I wouldn't be surprised if the number available is very similar to what we have today.
I'm half expecting quite a few season ticket holders to give them up once we move.... Not because they don't want to support the team, but the ability to pick and choose your games and have a good view from every single seat in the ground means there's less pressure to hang on to 'your seat' year on year. (obviously, if we suddenly morph into 1990s AC Milan people will keep them)