One of the biggest problems is that in many cases, the intendedI'm uncertain what scenario you are considering, but it isn't this one.
This scenario starts with messages that are delivered to the member, albeit possibly to Spam or some folder other than their Inbox.
In that case, there is no communication possible between groups.io andThat's generally not the behavior of major email services' spam filters. As long as the message source does not appear on a blacklist, and/or hasn't established a strongly negative reputation, the filter will tend to pick and choose messages to divert based on the message content.
In particular off-list notifications (such as the "resume" notice, or a even a member notice from the group's mods via the site) are not likely to be downrated just because group message traffic was.
So showing them how to set up any new provider account doesn't seem anWell, it certainly is an "impertinent" response, IMO.
I would only suggest it to Yahoo Mail users who might actually prefer another provider, but came over from a Yahoo Group having believed that it was necessary or better to use Yahoo Mail with that service.