Strictly, I believe that Groups is not closing, but is being cut back to discussions only - no supporting file storage, images, etc.
Which is more than a little ironic for those who bemoaned Yahoo's takeover of eGroups.com, turning our perfectly good mailing lists into horrible web fora (which we studiously ignored, except when necessary for administrative functions), and attracting an influx of new users who didn't know how to reply to the right message or quote properly.
It's only taken them about 19 years to sort it out...
I wonder if this means we'll get DejaNews back in 2021?