I do think Ion delivered good work for what he set out to achieve and i think he still believes he does, but is he with his focus on raiding and background the best person in charge to lead WoW forward?
Perhaps a new breath of fresh air is needed from outside of Blizzard to offer new perspectives, the last expansion simply felt that everything was build around eventually to start raiding and MMO's that are more diverse seem to attract people longer.
Shadowlands seems to offer something more geared towards solo progression but i am holding off pre-ordering till the "honey moon" phase dies off.