Depending on how the old units were viewed in the Free State post Independence recreating them could impact numbers joining up.
Ireland was basically pro allied “neutral” during the war anyway.
It's a good question, but given the successful recruiting for the 10th and 16th divisions in 1914-18, I wouldn't think so. As it was, the 10th, Division when originally recruited, had seven of 12 battalions raised by the regiments with traditional recruiting districts in Connaught, Leinster, and Munster, while the 16th Division, also when recruited, had nine of 12 raised in the southern provinces. The 36th Division recruited in Ulster, of course.