Yes, it's clear from that blog they don't have health insurance, they are only covered up to limited amounts for emergencies on the road. They admit that expat health insurance is what they should have, but doesn't really cover them since they are extended time in the US right now. Note that expat health insurance is not ACA compliant, unless you're out of the country for something like 335 days.
As a younger person, that is a risk you would have to take, as you wouldn't be covered for things like cancer. I will admit, I did go without for 2 years pre-ACA when I was 31-32 and only had travel insurance as I traveled around the world. Luckily, I had no health issues and found a job when I returned and was covered again in a couple months of returning to the US. Super lucky I didn't have any health emergencies in that time.