I think Kiel got really close to Bundesliga three years ago - lost the playouts against Cologne - and now they're winning in Nurnberg with one man-advantage. I'd be really disappointed if they didn't make it to BL.
His contract is going until 2027, he played plenty in the second half of the season, his wife was reportedly there when the club celebrated the promotion, and in this video from a month ago he seems quite happy. So I wouldn't expect any changes.