https://support.google.com/plus/answer/9217723?hl=en
Youtube appears to be fine
Google accounts have been disassociated from Google+ on YouTube for a while now. Google+ shutdown will not affect anything outside of Google+ for the most part. YouTube, logging into other sites with your Google credentials, and photos and videos stored in Drive attached to Google+ will all remain as they are.
If you saved videos directly to Google+ that were not put on YouTube, you have until April 2nd to nab them.
https://support.google.com/plus/answer/1045788 If the video is watchable on YouTube, it should be fine.
This shutdown doesn't affect Google Apps/G Suite's version of Google+, which is a separate (and surprisingly updated) offering. That shouldn't apply to most of us, but if someone says their Google+ is still up and working, that could be why.