Not a cold crash fan for a few reasons:
1. Rapid temperature swings (up or down) are stressful on the yeast. May help them floc, but it also may cause them to release stress compounds. Even if flavor profile is unaffected, stress reduces vitality of the slurry for the next pitch.
2. Cold crashing in your fermentor increases exposure/uptake of oxygen. Cooling liquid increases gas solubility and reduces total volume (increases headspace in the vessel). In an atomspheric environment, the headspace gained by reducing the volume is filled with air, and the oxygen in that air is more soluble at the lower temperature.
3. Cold crashing before bottling means (at least) longer carbonation times and (most likely) stunning the bottling yeast.
#2 is not an issue in a purged keg on CO2, but you still can stress yeast left in suspension with a rapid temp drop.
I'm sure there are tons of great homebrewers that make award winning beers by cold crashing in the fermentor. Its just not something I do. Its definitely not necessary.