I would have expected the incidence of vortex strikes to go down as susceptible roofs/tiles get replaced with better clips able to withstand the effects.
Although changes in procedures might make new areas more subject to vortex problems (? more landings on 09R).
And I thought that I had heard that there had been an increase in problems from further out probably associated with increasing fleet penetration of A380.
I was surprised that the initial press reports didn't link it with vortex strike :
Mystery bangs on roof leave firefighters scratching their heads / Royal Borough Observer / News / Windsor
although the Daily Mail pics would tend to have suggested it as a likely cause
Grandmother left with gaping holes in her roof after vortex from passing JET blasts the tiles off | Mail Online