It did start towards the end of last (football) season the e.g. 'Champions Weekend' or whatever it was called but from memory it was tending to point people towards Discovery+ which is probably going to continue.
I noticed a tweet yesterday from BBC Sport about their coverage of the Women's World Cup quarter finals and not one mention was made of any linear channels just iPlayer/Sounds/BBC Sport app and I think the WBD/TNT approach is going to be similar.
As for sports rights who knows exactly but I'd suggest WBD are the main player (even though it's 50:50 deal) and will buy out BT within the 4 years stipulated in the agreement. I've worked in a JV (different industry) myself and we all knew it was a sale/takeover in all but name and at the first opportunity the agreement allowed, the company we had worked for sold up shop.
