If miners know (and they will know) that price is going up, before the halving they will try to not shell, so there will be a shortage of mined coins before the halving, triggering a rally.
Is this correct??
Mined coins only make up a small amount of the coins sold every day. If there's more demand it's possible more hoarded coins will become available. A rise is far from guaranteed just because there are fewer new coins arriving every day. If there's not enough demand then the supply becomes less relevant.