I can’t help but think you are putting way more thought into this than you need.
The stats on the about page are updated using a regularly scheduled sidekiq task. You can run it manually by going to /sidekiq/scheduler on your site and selecting the trigger button for Jobs::AboutStats.
You don’t want to deactivate user accounts, unless you want them to reconfirm their email address before logging in again.
This is what you want. We do this on our internal site when people leave the company.
