Would they? Cause, if so, it, IMO, would be quite the political statement from the WAlies and it would be tantamount to as a matter of fact acknowledging Greece sovereignty over Constantinople and/or to the former imperial city as the new and restored capital city of Greece...
First, I was following the analogy with the Leclerc's Free French spearhead armored forces being allowed to enter first in Paris by their political and symbolic importance. Second, would in this situation, all of the Greek important enough, for their opinion would matter, political and religious figures/parties would accept it or agree on this ? And last, would Greece allies and especially, the Soviets, be aware of it or would they believe them?
Consider who provides the overwhelming majority of the troops to the Allied Armies of the Orient and who is the theatre commander. War is the continuation of politics by other means and Theodore Pangalos will understand that the Yugoslavs need to be front and centre when the border is crossed and for the same reason will make sure that the thrust through Thrace towards Constantinople is dominated by Greek troops.