Google's John Mueller has said before to keep your redirects in place for a year. John added that it needs to be kept live for "at least for a year" now, not around a year, so that you can ensure the redirects are "reprocessed a few times." He said in most cases, redirects are left in place for multiple years.
So when setting up redirects, make sure you have a plan to test to make sure they are redirecting properly for at least 12 months or longer. Maybe even set up a way to check how many times GoogleBot tries those URLs?
Here is John's tweet:
I'd usually try to keep redirects in place for as long as possible, at least for a year so it's definitely been reprocessed a few times. In practice, they often remain in place for multiple years.
— 🍌 John 🍌 (@JohnMu) April 27, 2020
Sometimes with redirects, you don't always have control - but when you do, keep these points in mind.
Usually if the domain registration drops, then you can't do anything like redirects. This is one of the reasons why we recommend keeping domains registered for a longer time, even when moving.
— 🍌 John 🍌 (@JohnMu) April 22, 2020
Forum discussion at Twitter.
Update: Carlos de Varona of Chroma House Productions, a video production company in Miami, was the one who asked the question and asked I mention that, so here it is.