Hi Tina.
I apologise for the experience you faced. This should be solved now for new users going forward as the messaging was updated on Friday afternoon to be more reflective of the actual action (Invite all employees, or choose who to invite).
In terms of the emails thereafter. Once an employee is invited to Flare, they are actually able to use the app even post termination, as the relationship exists between the employee and Flare. Disabling them as users doesn't prohibit the employee accessing any generic benefits from Flare, but will prohibit them from accessing any custom employer benefits you set up in your admin.
That said, the second reminder email I believe is the last one. They will not receive any marketing communication.
Regards
Itai