That rumors have origin in interview of former WADA president and incumbet member of IOC Dick Pound. He said that IF conditions will not allow games to be held when scheduled, they will be canceled not delayed because delaying / moving such a major event is practicly impossible. The media eager for the sensation interpreted it in a slightly different (wrong) way
I don't think many people had read his interview. His point is no delay this year as conflict with NBA or anything else. Mainly the broadcasters in USA will not agree. But the Olympics can delay to 2021.