As part of a Reddit AMA by Google’s John Mueller in August 2018, John was asked the following question:
“Do you think pages with 1 year old content are loosing (losing) ranking beacuse (because) Google wants to show fresh content every time?”
John replied with the following thoughts:
No. Fresher doesn’t mean better. Don’t fall into the trap of tweaking things constantly for the sake of having tweaked things, when you could be moving the whole thing to a much higher level instead.
One way of interpreting this response is that a site should not update content for the sake of making it ‘fresher’. If you are going to update your content simply improve it significantly.