The sooner, the better. That means the reviewers will get it in their hands and the next couple months will be real-world results. Then, the holidays will be right around the corner and hopefully, holiday price cuts. If the R5 ends up being as good as it's being described, it'll be time to retire my 5DM3 finally!
The reviewers have likely already had it in their hands for months. So expect a TON of videos to hit YT in the coming days.