In a private chat on Signal with about 50 Twitter staffers, nearly 40 said they had decided to leave, according to the former employee.
A separate poll on Blind asked staffers to estimate what percentage of people would leave Twitter based on their perception.
Blue hearts and salute emojis flooded Twitter and its internal chatrooms on Thursday, the second time in two weeks as Twitter employees said their goodbyes.
By 6 p.m. Eastern, over two dozen Twitter employees across the United States and Europe had announced their departures in public Twitter posts reviewed by Reuters, though each resignation could not be independently verified.
Early on Wednesday, Musk had emailed Twitter employees, saying: "Going forward, to build a breakthrough Twitter 2.0 and succeed in an increasingly competitive world, we will need to be extremely hardcore".