We used to do this at work. Then someone bumped the date in every file. I can point to PRs that copypasta'd old dates in from people who copied the notice from deeply ancient source files and claimed a copyright date ages in the past. Or files that were updated and nobody bothered to bump the date.

As a result I ripped out all the dates, with the blessing of our legal department, because they were next to useless. We've got a git history and while the dates there aren't perfectly tamper and error free, they're vastly better than all the nonsense we had our headers.

Pretty sure these dates are a software development legal cargo cult and would encourage anyone who disagrees with me to actually sit down with their legal council and go over the issues and publish a nice medium article if you think I'm wrong. And make sure to spell out issues like this one which opposing council would be sure to use where the date bumping on /bin/true is a clear violation of policy. At best it seems legally useless and at worst you've got a policy that opposing council can probably slam dunk prove that you are not following.