The sauce waits for the pasta, the pasta doesn't wait for the sauce. — You should have the sauce ready first. This allows you to sauce the pasta immediately, and this prevents the pasta from sticking to each other. [1]
The pasta doesn't wait, the guests wait. — Pasta should be served and eaten immediately once it's ready. Ideally, you don't put the pasta in the boiling water until after the guests arrive.
If you really have to wait, you can pause a little bit after saucing the pasta and before serving it, but the wait shouldn't be very long.