You might get lucky. Often once the next release is available for fittings, they will pull the prior release fitting kits. Titleist doesn’t post that data to us users, so you will to check with your local pro shop(s). The TSR-1 lineup is discounted even though they won’t be upgraded until after the PGA convention.
Inventory does play a role. I noticed the LH TSR-2 on the Titleist web site was missing a couple of lofts a week ago. Also not sure if all authorized dealers will keep rack models on hand after the GT release date of August 23 for retail.

I believe the fitters turn in their old heads when they get the new models. Am out of town on family emergency or would check with fitter.

Previous Gen models will not usually be available for a fitting. You may get lucky and find a great deal on Demo Models or existing inventory. They'll go quick as there are a lot of bargain hunters out there. I know a number of folks that will get fit prior to an upcoming launch and wait for the price drop.