I think Mozilla could round up various offerings that would require little overhead to offer (similar to reselling Mullvad as Mozilla VPN). To round up a few:
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nice idea. And it can be named as mozilla suite for hint of nostalgia.
Personally I think a white-label e-mail solution would make sense, both for individuals and teams. For example mailbox.org's model is pretty good I think (not an ad, I am a paying customer).
I don't think that those solutions are something they can maintain, they did in the past Firefox Hello integrated in the browser that was a chat with videocamera support like 10 years ago...
About Mozilla Hubs I still don't know how many people use it right now every month...