Biden is owned by the Chinese. It’s more likely he will order the defector returned to china, and all records of his testimony destroyed.
If the guy is smart he’s already met with Trump and done a data dump, the contents of which will be made public in the event of his demise a lá Wikileaks. He may no longer expect to be personally saved from a grisly fate but is likely trying to protect his innocent daughter going forward. Perhaps she has already met Ivanka.