Willson and William Contreras are now part of MLB history.
According to Baseball Almanac, 435 pairs of brothers have played in MLB all time. Per MLB.com's Sarah Langs, only five sets have earned All-Star Game starting berths in the same league in the same season: Mort and Walker Cooper (NL, 1942-43); Dixie and Harry Walker (NL, 1947); Joe and Dom DiMaggio (AL, 1949); Roberto and Sandy Alomar Jr. (AL, 1991-92); and now, the Contreras brothers (NL, 2022).
Willson Contreras was voted the National League's starting catcher; William Contreras will replace the injured Bryce Harper as the NL's starting designated hitter.