When you add new users to a recurring meeting, make sure you choose the option to send the update to All. This will update meet@chime.aws with the changes and new users will get called.
Note that we have seen situations where Google calendar is not prompting the organizer making the change to update all. A work around that we have found is to make another change (e.g. to the meeting invite text). This will force the update to go to all and meet@chime.aws should get the notification and make sure to auto call all the registered attendees.