I own a 2020 Legacy Touring…
I own a 2020 Legacy Touring XT. A couple years ago my windshield cracked for no apparent reason. I live in Michigan and it was winter and cold. There were no chips in the windshield, suggesting something had hit it. The crack started in the lower right. Two weeks later it spread to my field of view.
The windshield repair/replacement technician said he has seen many of these. He pointed out that there are heating elements under the lower right windshield to keep the windshield wiper from freezing to the glass. I don't know if that contributed to the failure or not.