To be honest, our FA super never said anything and we just set our own start dates with summer band. The hard-working directors that served in Birdville went above and beyond those extra-days anyways.
Districts do this because in the end it saves them money. If it means a lot to you, then hold your ground and contact your UAE rep. In my case, the loss was insignificant and not worth it.
Since this happened in Birdville, they never raised the stipends for directors. All Assistant Directors in that district are working the same amount of extra hours (if not, more) for a payscale from 2006. This could happen to you if you plan on sticking around for a while.
To be honest, unless it's written in the contract somewhere or somehow, then I can't see how having you come in early would hold up. I hope that someone or a group would fight this ridiculous way to save money and require the same workload.