In SharePoint Online is there a way to send a Web (a sub site) to the site collection recycle bin via PowerShell/CSOM?
I know that a web can be deleted with
Web.DeleteObject() but this does a permanent delete and this is not what I need.
This is one of those annoying things which work in SP OnPrem and not in SP Online.
Unfortunately, we don't have capability to send the SP Web to recycle bin programmatically in SPO. The method to do that is not available right now via CSOM, PowerShell or REST APIs. It can be done via the UI though.
There is a uservoice request for this as well which you can upvote.