I have a Meteor web application hosted by Heroku. I use Iron Router for the routing layer. I am able to navigate to the homepage, assigned to the / route, without using the www prefix in the URL. However, navigating to any other route by typing the url in the address bar without using the www prefix will just redirect to the homepage. Internal site links using iron-router's pathFor work fine.
EDIT: I found this exact same issue on the serverfault community: https://serverfault.com/questions/617248/does-google-domains-support-cname-like-functionality-at-the-zone-apex
No immediate solution was provided there either. I'm investigating CloudFlare as an option.
David, I have an idea which is not for a straight Meteor solution, but maybe this will let you solve your problem.
Go to your domain configuration at your domain provider panel. Create redirect of the www address to non-www address of your website. As long as I have same site displayed on both addresses I always do it this way, and it works like a charm.
Keep in mind your domain propagation time (6-36 hours).