I'm currently helping out on a beta site. One of the most valuable things on new beta sites, especially private/early public betas, is Meta participation - see this mod newsletter:
Treat Meta Questions Like Gold
It’s not unusual for your meta site to receive significantly less traffic than the main site. The problems begin when you meta starts to get ignored by the community and ignored by the moderators. It is particularly disturbing when users reach out in meta and starts talking about improving the site or asking for help… only to be ignored; No follow-up, only deafening silence
Because of this, Diamond mods get a notification in their inbox for each new question on their Meta, helping ensure that each meta post is addressed.
However, wouldn't it be great if Diamond mods weren't the only ones that could do this? The post does say that the community needs to be seeing these questions too.
As an involved user, I would really like to be notified of these new questions - it would increase the good I could do the site. How about this?:
Of course, it would be opt-in, not opt-out, and per-site. A feature like this would greatly improve the good that enthusiastic site-builders can do for the site, and would, most likely, increase the overall chances of a site's success.