Comcast Corp.’s new streaming service Peacock is about to get a large boost from sister movie studio Universal Pictures.Starting in 2022, theatrical releases from Universal-including the next “Jurassic World” and new “Halloween” movie-will have their TV debut on Peacock, the streamer initiated by its parent company last year.The movies will appear on Peacock no later than four months after their theatrical premiere, joining other studios drastically minimizing the length of time they usually wait to make their biggest release available on the small screen. But it also gives Universal a much-required advantage regarding its streaming competitors with every studio’s largest releases are made available as soon as possible.By giving its Peacock service greater priority in distribution, Comcast continues its focus on direct-to-consumer offerings that value subscriber growth and retention over all else. Competitors at Walt Disney Co. and ViacomCBS Inc. have taken similar approaches that use marquee titles from a decades-old studio to strengthen the appeal of relatively new streaming services. With Wall Street watching for any indications of subscriber losses, studios and their parent companies have broken once-sacred practices to give their services an edge.