Sorry for being so late to this topic. I think the approach we want developers to take is to encourage people to follow their account on itch.io. We already use follows to handle sending digest summaries of devlogs. The idea would be that you would do your marketing style announcements via the devlogs system. This also gets your update syndicated on our devlogs system so people can discover it via the web as well. There are other benefits for developers to encourage their users to follow them as well: we can automate all different kinds of notifications like the aforementioned devlog updates, new game available, games on sale, etc. You don't need to remember to write emails for that stuff, or try to manage individual mailing lists. And users have more fine grained control over those types of notifications.
Also as an aside, we don't collect contact information about people who download things for free. Many people download free accounts without ever creating an account.
I think there's definitely more we can do to encourage people to follow accounts, but sometimes having the developer say it as well can go a long way.