I've checked the existing answers on this forum and the most recent one I found was from 3 years ago. Is it still the case that videos with hotspots can't be uploaded to Vimeo and retain the hotspots? IS it only Screencast that will retain them?
That is indeed the case; Vimeo does not allow interactive elements, such as hotspots, quizzing, or a table of contents, on videos. If you wish to use those features, you will need to host your videos on your own web server (see here) or you will need to upload them onto Screencast.com.