I noticed these roots coming out above soil level this morning. Should I add more soil or leave it as is? This is an Adriatic JH.

It is the soil settling down over time. Not a big issue but adding some soil to cover can make the plant a happy plants.
I see it often with my plants but procrastinate to add soil (though eventually I add some when I get a chance). 

Hi,
Could be the tree growing into the mulch or could be that the soil settled. It looks like you're watering on the base of the tree - thus moving the dirt away.
If the tree is growing strong, you need to add soil to your containers.
I definitively would add soil and add mulch over the soil ( like it was before it seems ).
As you water, you may need to add more dirt as the water will take the new soil down in the container.
Last year I had to add a bucket of loam to one of my 80liters./20gallons containers ... I couldn't believe it. it was like the tree was eating the loam .