No, policies aren't inherently bad, but wide-sweeping policy changes for perceived problems or in response to relatively few bad actors are company killers. You might not see it right away, but your people who have options will leave you eventually.
The part that's bad in email 2 is "we've decided". No one likes being a slave to anothers will or reminded of the fact.
If I ever send out a bs policy update without discussing informally with staff or managers beforehand I expect everyone here to walk.
We spend a lot of money hiring talent. They do whatever the fuck they want so long as they get the job done. If they're not getting the job done, then we talk. We don't punish everone for one guys non performance.
Wait, what are you talking about? WE decided? MY best interests? How do you know what MY best interest is? How can you say what MY best interest is? What are you trying to say?