You need to balance letting your manager know that this is a bad way to manage with the likelihood that your manager will forget about this. Managers should let you know early if things aren't going well so you have time to course correct. They also shouldn't leave new juniors alone to make important architectural decisions. On the other hand, to the extent that this "counts against you" if you don't say anything about it your manager will likely forget it happened in a relatively short time.
I would create a list of your manager and his peers. Record how long, approximately, they've been in their current role then average those times.
If the number is short, like six months, then I would let this go on the premise that, in six months or so you'll probably have a new manager and it's just not worth arguing about.
If the average tenure is much longer then I'd wait a week and implement as much of the feedback as possible. Then I'd schedule a meeting with the manager to go over what I'd done in response to the feedback and raise the concern about late feedback.
I would create a list of your manager and his peers. Record how long, approximately, they've been in their current role then average those times.
If the number is short, like six months, then I would let this go on the premise that, in six months or so you'll probably have a new manager and it's just not worth arguing about.
If the average tenure is much longer then I'd wait a week and implement as much of the feedback as possible. Then I'd schedule a meeting with the manager to go over what I'd done in response to the feedback and raise the concern about late feedback.