Yep, I agree, it's most likely the throw out bearing.
Also, I'd replace the clutch fork ..... it may be bent/cracked (something made the bearing go bad).
When you come up to a stop, do you have a habit of holding the clutch down ..... or do you slip it into neutral ....and release the clutch ... ??
My feeling is that the dealership should replace the bearing under warranty. I wouldn't consider it a "wear item", at 20,000 miles. Maybe yes, at >150,000 miles.
If the dealership doesn't decide to fix it under warranty..... you tell them that for the price of a throw out bearing and labor ....... they DO NOT want FR-S Forum "over the hill gang" coming over the hill down into Monterey at them ......
I hope you get er fixed up soon......
humfrz