Hey there.
Yes – v6 of the tasks now download the scanner from GitHub. This was done for a few reasons:
- No longer require a new release of the Scanner for Azure DevOps to allow users to use the newest version of the scanner
- When there’s a bug in the newest version of the scanner, make it easy for users to revert to an older version without having to release a new version of the task
And as far as I’m aware there was supposed to be a helpful message to tell you what to do in case you don’t have access to the internet… 
I’m following up on that.