This is part of a message I received today about Google+ being shut down. This includes Youtube.

In December 2018, we announced our decision to shut down Google+ for consumers in April 2019 due to low usage and challenges involved in maintaining a successful product that meets consumers' expectations. We want to thank you for being part of Google+ and provide next steps, including how to download your photos and other content.

On April 2nd, your Google+ account and any Google+ pages you created will be shut down and we will begin deleting content from consumer Google+ accounts. Photos and videos from Google+ in your Album Archive and your Google+ pages will also be deleted. You can download and save your content, just make sure to do so before April. Note that photos and videos backed up in Google Photos will not be deleted.

The process of deleting content from consumer Google+ accounts, Google+ Pages, and Album Archive will take a few months, and content may remain through this time. For example, users may still see parts of their Google+ account via activity log and some consumer Google+ content may remain visible to G Suite users until consumer Google+ is deleted.

As early as February 4th, you will no longer be able to create new Google+ profiles, pages, communities or events.

See the full          for more details and updates leading up to the shutdown.
I got the same email, but Youtube is not mentioned at all.
I looked at my history and I'd made exactly ONE post on Google+ several years ago.  LOL
Geoff Z
I got the same email as well. I assumed it was because our Ziller email runs through G Suite. I had never heard of Google+ before that email. My IT guys said the change will not affect Ziller.
Google Plus was Googles stab at social media like Facebook. It was a way for Google users to share and post in a group forum. If you didn't use it (few did) it has no effect on you.
The massive security problems in Google Plus pretty much left them with little choice: