It already exists - it’s also known as Jordan which is in east Palestine.
People still say that. It was only Zuheir Mohsen that made that claim AFAICR, and he was a “Palestinian” that liked to mix lies with truth, although in this context it was in regards to the lust to take over Jordan under a new Caliphate (as ISIS recently proclaimed under their own banner). Jordanians are fiercely independent from “Palestinians” to this day—they know they are not the same people.