Marcelo Bechler is the journo who broke Neymar to PSG two years ago. He is brazilian but is based in Barcelona, he has good contacts. The source is trustworthy.
Only detail is that he didn´t translate the end of the tweet in portuguese. It says that other europeans clubs are watching Reinier´s situation and could yet make a move for him , after all the transfer can only be completed when he turns 18.