Could Dunkirk have become a reinforcement bridgehead?

Could the Dunkirk evacuation have been reversed into a reinforcement operation that held the enclave?

Only with a different campaign and pre-positioned troops, shipping, and amphibious support; those conditions did not exist in the historical crisis.

The physical act of sending troops back across the Channel was possible only under a substantially different campaign. Reinforcements had to be ready before the crisis and supported by enough amphibious shipping to cross the beaches. The enclave also needed a defensible military purpose within the wider Battle of France. Without that prepared system, evacuation preserved the army while reinforcement risked trapping additional formations.