A PR analysis does not detect S1200. When using PR anylsis and PR decoration you would not see the issue until you merge it to master. On master it will fail, but this feedback is too late.
Product
SonarQube 8.6.1 Developer Edition
Reproduce
Create a class with too many dependencies (Java has a default of 20). Scan it with PR analysis. Compare it with branch analysis scan.
Workaround
Don’t use PR analysis + decoration, but use branch analysis.