Someone on the SwiftKey Insiders forum asked about this topic and I thought I would share what I did there.
I did a SwiftKey beta feedback report back on April 12, 2019 asking about the status. On May 20, 2019 (yes, over a month later), I received a response with the following information:
Matt Farrington Smith (SwiftKey)
May 20, 7:12 AM PDT
Thank you for reaching out to SwiftKey Support.
You previously contacted us about adding SwiftKey Clipboard support to Windows 10. This feature was due to be released but development on it has since been paused – we will of course be sure to update you should this situation change or we have further news to share on it.
We appreciate your interest in SwiftKey in the meantime.
To say that I’m not impressed with the very late response is an understatement. Of course, I am disappointed and Microsoft has totally screwed this up. Being able to copy/cut and paste across Windows 10 devices is nice, but being able to do it across Windows 10 and iOS and Android devices is more useful to me. Yet, it is beginning to look like the Cloud Clipboard functionality is dying or not really going anywhere.