Or is it a nonslip coating that was factory applied? 

A new coat of paint and improved landscaping does wonders.

I am curious if a scope of work that contains "refinish hardwood floor"  is ambiguous and thus open for a variety of interpretations.My understanding going in was that the phrase "refinish hardwood floor" involves sanding the hardwood floor flat, probably using a drum sander, often, but not always staining the floor, and then finishing it with multiple coats of polyurethane.

Updates include recessed lighting, quartz counters, new vanities, new fixtures, and a fresh coat of paint throughout.

There are some things a coat of paint can’t hide.

As an alternative to removing the existing boards, you could apply Zinnser or Kilz (at least a couple coats) then add 1/4" Luann or 3/8" plywood over the existing once its' been sealed then apply your finished flooring.

My name is Jordan Coates and I'm a new investor from Smithfield, NC 27577.  

The concrete was actually thicker than first thought.

Agents sometimes sugar coat the message.

After using Killz (and several gallons, several coats) it has not worked.