Precedence means the White zone robots are more important, so they get the privilege of placing their robots where they want them after the Goalie robots have been placed. Not precedence in the sense of who goes first.
But “go first” is exactly what “precede” means. I wouldn’t even have considered a “more important, thus goes last” meaning before I saw so many people presenting it here. This is a wording issue that I think needs clarification in the Q&A.
Unfortunately, Chief Delphi is a poor source of information about rules clarifications. The GDC is available at the Official FIRST Question & Answer website, where your question will be available for other teams and referees as a binding interpretation of the rules.
Seems almost everyone agrees that this was a poorly worded update, including me. I don’t think changing “precedence” to “priority” will help much, since it still means “going first” (Merriam Webster says “something that is more important than other things and that needs to be done or dealt with first” - emphasis mine).
Maybe in the next clarification, they could say something like, “TEAMS positioning ROBOTS in the white ZONE may move their robots after opponents placing ROBOTS in the GOALIE ZONE.” Maybe add something about it being at the referee’s discretion.
The rule update is to prevent a goalie robot to be placed directly in front of where a robots auto shot is lined up. The rule lets the white zone robots get to have preference of place so they can line up there shots around a goalie.