What's the bigger opinion on this. Is MS pushing onPrem Exchange as rotten apple to encourage the shift to 365 or are they genuinely pushing this info out for Administration awareness?

I would assume at this point any Orgs using onPrem are needing the services and thus assume it's for awareness?

Holy hell interesting read

Please, help me to understand something about MS Office.

Why the hell you can run a macro in a spreadsheet that can execute arbitrary PowerShell scripts? Why is that feature needed for MS Office users? Is it too hard that it just do stuff inside the spreadsheet and nothing else?

This doesn’t make a lot of sense to me. No on prem Exchange admin worth a damn is reading emails on the server, or reading their email and opening excel files and enabling macros in them using their admin account for that matter. The bare minimum of security practices will stop this thing before it ever gets started.