Typical Microsoft - just ignored all the people saying "please don't do this".

When you pause while debugging, you can hover over any delegate and get a convenient go to source link, here is an example with a Func delegate.

If you already know about delegates, there's not a lot of content in this dev blog post. Not that that's necessarily a bad thing either.

Available and enabled by default from version 17.11 Preview 2 onwards.

New resource explorer additionally supports search, single view across solution, edit multiple files and locales at once, dark mode, string.Format pattern validation, validation and warnings, combined string and media view, grid zoomability

Is there an extension that allows for automatic stashing on branch switch like GitHub desktop does?

There was an a proposal about it, but it got declined: https://github.com/microsoft/vscode/issues/86668