When Tom Bulleit first developed Bulleit Bourbon, at Buffalo Trace, he touted it as "reengineered" bourbon, and what he described was heat cycling. Woodford practices it pretty religiously. Both Brown-Forman and Buffalo Trace not so much, as Fred descibes in BT's case. I think at both places they have looked at the cost of heating those spaces versus the actual benefit. I wouldn't be surprised if their commitment to heat cycling varied with the cost of energy.
There are other factors to consider. The people with masonry warehouses heat them because they can. Keeping the temperature above 56, for example, isn't exactly duplicating summer conditions but it does promote some activity in the whiskey and makes the working environment more comfortable for the warehouse hands.