After mentioning the usual "Betteridge's Law" implications, my answer is "if they do, then the company should account for the time it takes and set release dates and such appropriately." Support is not something that can be just added to responsibilities without consequences.
I agree entirely. If I were forced to do support calls 6 hours a day, I'd rather not be expected to make those 6 hours up developing off hours. Especially to meet deadlines that don't take the support into account.
