You can subscribe to the relevant Announcements category for the type of release you are interested in. 
You can find more details in the welcome post including some more information on how to subscribe to the announcements:
Somewhat related, you can also manage your community email/notification preferences from your community profile. For example, some people like to receive a weekly digest of the community to keep up with posts as there’s often good information outside of the announcements:
Tap your profile image in the top-right corner of the page and then tap the preferences cog.
Select Email from the left menu and then adjust your preferences accordingly:
