Don't think he is tbh. Lost a large chunk of last season after showing potential he mey break into the side. We may have still got some poor results in those early games, but he was definitely looking up for it last July.
Regardless of whether there's a release clause - I would expect there to be and I'm not naive enough to think he'll definitely be here for 5-10 years - he has clearly seen a reason to stay, and that is good enough for me and progress in itself.