As the COVID-19 pandemic leads to more concert postponements in Toronto — notably K-pop band BTS’ two nights on May 30-31 at Rogers Centre and Roger Waters’ two evenings at Scotiabank Arena on July 17-18 — the chances of the city’s outdoor summer concert season starting on time is looking slim.In fact, a new Billboard cover story suggests touring won’t start back up again until at least July.This year’s Budweiser Stage was supposed to launch its outdoor season May 21 with The 1975, but the British band announced on Twitter on March 18 that they had to reschedule their North American tour “for the health and safety of fans and crew.”Live Nation Ontario is advising ticket holders to keep checking online for show status.“We are working with