I see two main questions here:
1. When I make changes to views or dashboards, will they show up in Tableau Online automatically?
If you make the edits in Tableau Online - they will show up automatically
If you make the edits in Tableau Desktop - you'll need to republish the view
2. Can Tableau Online see you live data on your SQL Server
You'll want to review this page for various approaches to this: Use Tableau Bridge to Expand Data Freshness Options
Thanks for reaching out.
So when I publish my workbook to Tableau Online with live connection, Tableau online will not automatically add my data source / data connection ? If you visit this link, Microsoft SQL SERVER is a supported database for the connection.
Tableau Online tips: Extracts, live connections, & cloud data | Tableau Software
Have I misunderstood anything ? Just to have a clear understanding Tableau Bridge will be used if the live connection is an unsupported database ? right ?
If your SQL Server is hosted in the Cloud, then Tableau Online can connect live to it. If it is hosted on your internal network, you'll need to use Bridge
A common misconception is that Tableau Online can only use data extracts. While that once was the case, we’ve made strides in offering live connections for common cloud data sources. Tableau Online currently supports live connections to the following cloud-hosted data sources:
- Microsoft SQL Server