The studio I use, wanted leadsheets until I started submitting midi files.
I still do leadsheets and believe they should be made available even if whoever is using them bends the progression a bit to suit them, it gives them a starting point as to where the write is comeing from and aiming for.
I have heard so way away from my targets when I gave them no direction in this manner.
If it is being done live, I can't imagine them not wanting a leadsheet.
it used to be standard proceedure to the best of my knowledge.
Graham