Necessary? No. Beer will clear given enough time.
Helpful? Maybe. Your mileage may vary. Adam1966 is right - give it a go and see. I have just cold crashed and used finings for the very first time. I've also put my bottled Golden Ale outside, but didn't think to keep some indoors as a control. I'll try that next time with the Wherry.
I'd still chill them before drinking.
By the way, I number the bottles as I fill them, so I know how far down the bucket it came from. It would be unfair to compare bottle #2 to bottle #37 for clarity, although I would hope they were both crystal clear.
M