United hasn’t committed to free WiFi, but has mentioned it as a goal previously.
https://www.khou.com/mobile/article/.../285-608152242
Even DL expects it to take a few more years to become a reality. UA going free today would tank the service so hard it would be completely unusable. Given current bandwidth constraints, I prefer it to be ~$30/TCON so I know that I can count on it when I really have to get work done.