I guess I haven't been paying attention to news at Yahoo.
They've made noises suggesting they'll eliminate listserves?
There are many small (1-3 person) businesses whose primary
email address is at a free email service like Hotmail or Yahoo.
When something goes wrong, they are surprised to find "there's
no there there" when they look for tech support. I've also
seen small businesses who did have their own domain and reasonable
email service, but who still used a free email account for some
small yet business-critical function. Same thing.
If you could download a backup copy of what's on the listserve,
it might be a different story.
I even backup my Gmail on a roughly quarterly basis.
- John