There is now two very distinct options for deactivating a patient.
Is reversible, don’t stress too much when using this.
Oh my, this is not reversible, I hope you know what you’re doing!
So really it’s not reversible, we wipe it completely from existence on this planet. Use it wisely. When deleted, appointments are not removed, but can be anonymised if you like (there’s a new setting in Settings > Patients > Patient privacy). Invoices also behave the same as appointments, with a setting in the same location.