Yes and no - in public it did but in private the volunteer group was well supported by the Administration.
http://www.warbirdforum.com/vets.htm
It's like a number of other ways that the Neutrality Act was bypassed. Another example was the British acquisition of Hudsons in 1941. Because they could not be flown out the States (a provision in the Act), they woul dbe flown to the border with Canada, manually towed across the border, and then flown to bases in Newfoundland etc for the ferry trip across the Atlantic.