Probably refers to first century Jerusalem and the destruction of the temple.
Remember, Christ said “This generation shall not pass.”
Also, Israel had been unfaithful yet again in rejecting God’.s Messiah.So while there may be reference to future destruction, it certainly does not ferer tot he destruction of Christ’s Church.
Jesus picked twelve Apostles, 11 of whom abandoned him the night he was betrayed by the twelfth. Jesus didn’t destroy his Church over that, and he’s not going to destroy it because it is currently run be blasphemers and Heretics.
He has a better idea....