Ummmm, the ships that were under construction were all already fully funded. That was one of the reasons the other naval powers were so eager to agree to a naval arms treaty. They knew the US was the only country that could actually afford to get into a naval building race. Not that Congress wasn't thrilled to get that money back, but the ships themselves were already budgeted for and funded
While we will never know for sure what would have happened in an alternative history, what we do know was that in late 1921, when the US firmly believed that both the British and the Japanese were going to build their projected battleships and battlecruisers, every leading member of the US Government, including the President, SecState, SecNav, and the big Navy leaders in both houses, was of the belief that there was no chance at all that Congress would fund the completion of the capital ships already laid down under the 1916 program.
This is simply not true. Funding was allocated on a year by year basis. They were fully authorised, but the Navy had to go back to Congress each year and ask for money to be allocated for the next years phase of construction - and nobody who counted believed that they would keep getting it.
