There's been no confirmation he's signed (or been offered) a new contract, let alone one at £20k/w.
All that has been confirmed is that Wolves took up the option in his contract to extend it for a further year (which may have included a pay increase and could be for 20k/w for all I know)
This gives Wolves the right to negotiate a fee with other teams, and he's apparently in demand so could get a bit of a bidding war. All they have to do to get that is sign a bit of paper on an existing contract.
On the other hand, they could've decided to NOT take up that option and renegotiate a contract for the same amount of time on more money, which Bright could then turn down and Wolves would only get whatever compensation they were due as a development fee, which would likely be far less than they can negotiate for him under contract.