Using classic Outlook for Windows in business environments
Hi Frubbl - I totally understand your frustration with the changes. With that being said as a paying customer of Microsoft 365, nothing changes with those apps and services. Outlook that comes with Microsoft 365 continues to work and supports OAuth via Outlook.com Syncing. You also continue to get all of the added benefits like Ad Free experience and additional storage for your mailbox and OneDrive.
Sadly we are unable to comment or force a vendor to start using a more Modern Auth mechanism. This change that we are doing to eventually retire Basic Auth is not unique to Microsoft. In fact Google has already completed their deprecation of Basic auth/Less Secure Apps, and we know a variety of other ISPs that are in the same process. This change that all are going through is truly for the safety and benefit of all of the users.
So the best suggestion that I would have is to start discussions with BlackBerry to see if they are planning or will be supporting more current forms of Auth. This is the same way that apps like Apple Mail, Google Mail, and Thunderbird all have started to support OAuth in the past years.