it was only optional to avoid a breaking change in a minor
BREAKING CHANGE: The `currentSnapshot` parameter in `CanMatchFn` and the `canMatch` method of the `CanMatch` interface is now required. While this was already the behavior of the Router at runtime, existing class implementations of `CanMatch` must now include the third argument to satisfy the interface.
PR Close#67452
Currently internally Angular has some customized tsconfig files, because we don't align with the tsconfig of the rest of g3. These changes enable `noImplicitReturns` and `noPropertyAccessFromIndexSignature` to align better with the internal config.
PR Close#51728
This commit updates the docs of the functional guards and resolvers to improve the migration
experience when moving away from class-based equivalents.
PR Close#48873