Why is anyone surprised? The Tories have always been against grammar schools.
As Education Secretary, Thatcher (who sometimes came as close as possible to claiming to have attended a state grammar school without actually telling that lie) closed so many of them that there were not enough left at the end for her record ever to be equalled. During a very prolonged period in office, the Tories made no effort to reverse comprehensivisation, because, far from being Socialist, its suited, and suits, their requirements to a tee, with strict selection by parental income through either or both of fees and house prices.
As for Labour, comprehensive schools were what it came up with when it gave up (a very long time ago) on serious wealth redistribution. "Equal Opportunities", "meritocracy", and all that. Nothing to do with Socialism at all, to say the very least.
Still, it is notable that a vote for the Tories is now a vote to close down even the grammar schools that still exist. But again, why is anyone surprised? The Tories have never done anything to defend the grammar schools. And why would they? Indeed, how could they? Even in flagship Kent, that job has been left to Eric Hammond. Of course.