According to Todd Zolecki, the Phillies will not be bringing Chris Young back as their pitching coach next season:
It was one year ago that the Phillies dismissed Rick Kranitz as pitching coach, and promoted Young who had been serving as Kranitz’s assistant. Young was believed to be highly sought after by other teams, and the Phillies felt that his approach was a better fit with the team’s overall philosophy on pitching development.
The move did not work out well. The pitching staff - which seemed to take a step forward under Kranitz in 2018 - performed poorly in 2019.