The Weather Channel is a standard cable network. Cable/satellite and similar (YouTube TV etc...) PAY them to carry it. It's EXTREMELY unlikely it would ever be available for free.
For streaming to a TV, there is the Weather Channel app. It's $3/month or $30/yr. You get the same live feed, and access to OnDemand content. For phones/tablets, there is a separate app and subscription.
https://streamtwc.com/
