From Sigma:
SIGMA 24mm f/1.4 DG HSM | Art F/CANON and SIGMA fittings are scheduled to start the shipment towards the middle of March.
SIGMA 150-600mm f/5-6.3 DG OS HSM | Contemporary F/CANON fittings are scheduled to start the shipment towards the middle to end of March.
B&H lists an expected availability date of March 20 for the Sigma 24mm f/1.4 Art Lens and 150-600mm f/5-6.3 DG OS HSM Contemporary Lens for Canon.