Workaround was added in https://github.com/angular/angular/pull/25335. It was necessary for .ngfactory & .ngsummary files to have proper AMD module names starting with @angular when building angular downstream from source using Bazel. The underlying issue has been resolved in the compiler and these files now get proper AMD module names without the need for this workaround. The workaround had an unexpected consequence https://github.com/angular/angular-cli/issues/11835 which is fixed by its removal.
PR Close#25604