“The personality that now exists is a new entity… it is a merger of Bruce Banner and the Hulk.
There is Maestro Hulk, the evil, older version of Hulk who rules over his planet with an iron fist.
In answer to a question regarding the state of the Hulk post-Endgame, they confirmed that Bruce Banner is now permanently fused with his green alter ego.
After all, ‘Regular Hulk’ and ‘Smart Hulk/Professor Hulk’ are just two incarnations of a character that has undergone a wide host of changes during his lifetime.