1
Tanaka, Darvish, Ichiro, Ssaski, Johjima...all of them. At all skill levels. All of them have had it written into their contract that they were unrestricted free agents after signing. Iwakuma even had it written in that he could not be QO'd at the end of his deal. As did Cespedes. As did the Cuban Missile Crisis (Chapman).
That is just expected.
Ohtani will do the same. They are all treated like free agents if they are being signed to start in the major leagues immediately.