To a point, but sleeping before redirecting on the server is insanity. It's pointlessly brittle when the client is perfectly capable of managing its own timer.
This approach completely breaks sensible reasoning about what clients are responsible for. What's next, sending every keystroke to the server so it can tell the client to update a text input?!?
It still takes resources to keep SSEs open, load balance, reopen lost connections, etc. But worst of all is shifting fundamental logic back to the server for literally no benefit.
It's a toy example, it's suppose to show that you can be doing N things and then redirect. If you have a normal redirect immediately, just do a 307 or whatever.