Note that KJ can take a solid minute to imply that they're matching but can't say it unequivocally. There's a reason for that.
They aren't matching and it's unlikely that they commit to do so. It's not easy to make money off of an NBA team in a middling market whose residents have little spending power with zero chance of the big bucks from an RSN. Putting down a $525m valuation ain't worth it, it'd be a charity move. Take into consideration that if they entered into a binding agreement with the Maloofs to match the offer if the Seattle bid is denied, they'd be doing so without a binding arena deal. They'd then own a grossly overpriced NBA team relative to its market and that city council would have a ton of leverage to work out a deal (keep in mind that they really haven't worked one out, just a list of ideas) in their favor.