Migrate CRM Analytics Connectors to OAuth Before Winter 27 - which connectors exactly?

Hi all, 

Recently I received an email from Salesforce on the subject I put in my header. I have read it several times and also clicked the added links but I cannot fully understand what the impact is here. 

Not sure if this is about External Connectors to other Salesforce Orgs only or if it also about External Connectors to an Azure SQL database. 

Also I am a bit surprised about the seemingly short notice on this change. Does anyone else have similar questions and/or an answer to my question