I think most extensions are meant to keep a coach in place/guarantee their job through the year before. So in this case 2025.
It is a real grind of a profession and I think it's easy to see why someone would want to stay around the game (broadcasting) AND make ridiculous money while not working themselves to the bone into their 60s. He'll probably have a young family in a few years too.
He will turn 40 during the 2025 postseason.
I'd love to see an even 10 years as HC (through 2026) but I think that's the absolute latest he'd ever be around.