Hey Kyle,
Good point. We alway have an Ubuntu 16.04 image available with 18.04 in the pipeline for this year as well.
The default machine image may still be 14.04, but if it is it should be changed any day now. I’ll check in by Monday to help make sure that happens. That change should be happening today according to our previous announcement: Default machine executor image update
As far as the Ubuntu 16.04 image being broken, that I wasn’t aware of. I’ll check that and follow up here.