I bet they don't mean any offer. They're not paying him the max. Regardless, for the Celtics to have signed Hayward, it probably was going to have to be through a sign-and-trade, so I don't think this changes much anything. The Jazz are mostly telling other teams that if you really want Hayward, give a call before making the offer sheet (since by league rules, once Hayward signs an offer sheet, a sign-and-trade can't be negotiated). By sending this message, it will also drive down interest in Hayward, and ultimately lowering his contract
Expect similar language coming from Ainge about Bradley. It's all posturing.