I don’t believe in anything that anyone says unless I see proof. This person doesn’t have any proof of the writers/directors/cast stating this. This person is either misinformed or is trying to get the Hook fans into a frenzy.
And there is no way that the show can lose the rights to Hook this quickly. When a company gives the rights to a show/movie, the show explain how they will use the character and the company must agree to all this to give the show their rights. They can’t just pull out and make them stop using the charcter; this is all signed.
But I highly doubt that Once Upon a Time would lose the rights to Hook because ABC (or is it Disney) would know what they are using the character for and obviously approve of it. Why would they suddenly change their mind.
Don’t worry, Hook is here to stay for a very long time.