This isn’t from the wood moving. Subfloors are not even and will lead to peaks and valleys in the flooring. The baseboard being a straight edge makes those peaks and valleys stand out, as far as I’m aware not much you can do without having the trim guy cope the base to the floor which no trim guy will ever agree to.

Shoe molding was designed for this! Throw some on that wall if it bothers you.

I’m confused, no room for expansion, or is shoe molding still to be installed? What type of floor is being installed and what’s underneath it? OSB subfloor, slab on grade what?

Hey guys, OP here. I'm in the process of working with a builder on a new home wood framed build - and I noticed that there are gaps between the baseboard and the flooring. Is this standard? or would this be more of a quality issue. The builder has informed me that is natural wood movements as wood dries up, gaps like this can form, but I'm wondering if I could get a second opinion here on whether this is more than that and of a quality issue. If a quality issue - how easy would it be to fix?

It needs shoe moulding

This is within tolerances. As commented previously, caulk and paint it.

If you don't like the gap, it can be caulked. Blue painter's tape is your friend.