I know that it is a little late in the season to be brewing a Pumpkin Ale, but something has to go into that empty keg.
I am planning to bake the pumpkins, scoop out the “meat” and add it to my mash.
I know that wine makers will freeze their fruit, thaw and freeze again to aid in the breakdown of cell walls in the fruit.
Would this process help with my Pumpkin Ale?
There is no reason to think it won’t. You can even delay your brew day for some time that way. I have a pumpkin in the garage that may need to see that process. Great idea.
I don’t think freezing will benefit you. The baking of the pumpkin will break down the meat on it’s own. I make fruit wine, and freeze some varieties of fruit to help extract the juice, but with pumpkin wine you just bake it and make it. 
Although you can freeze the pumpkin meat after it is baked, to use later. Good luck to you!