I just special ordered three 5 gallon multi-trunk Natchez for my back yard. However, when I went to pick them up, they were all single trunk with multiple branches starting at about 1″ from the soil line. All my research left me with the expectation that a “multi” trunk specimen would actually have multiple trunks coming up from the soil. Do all propagated CMs actually start out as single trunk and are just pruned into multi-trunk? The desired end result is V shaped and am concerned these may end up in a U shape with the branches coming out horizontal at first before turning upward. I want to make sure I can prune to the desired shape before committing to the sale.

I have many multi-trunked Crepe Myrtles. I did not observe their infancy, but none of them display a U shaped conformation - if that is any help to you.

That sounds like bait and switch...
Advertise multi trunk and not have them.

Crape myrtle are notorious for sending out new growth from the roots... It's nothing but a time issue....
There's no need for pruning, it's a thing they do, and we spend our time on our knees, cutting all those sprouts back down.

If you haven't committed to the sale yet I would go somewhere else. When I worked at a Nursery we would get equal numbers of single trunks and multiple trunks. But if you like them you can let them grow for a a year or two and then pick out the trunks you like and cut the others away.

I bought 3 single trunks 4 years ago. One is a dwarf. They are growing slowly due to not enough sun, but I knew that. But they are still single-trunked. The mature, 25+ years are multi trunked CMs (5) but started that way. Only one has sent up a sucker tall enough to call it a tree.

rbranch17! I think what matters is how much you paid for the crepes. We just got one the trunk was not the best and it is not the cultivar that it was tagged as. It was only $5. Now I realize you probably paid alot more. Check with two reputable nursery's in your area and just compare what they have, price, size, quality. My other experience with crepes the smaller they are, not blooming, they have a high rate of being wrong cultivar. Once you compare apples to apples and all things considered did you get fair market Crepe value for your money. I personally would not buy a LARGE Crepe in anything under 20/25 gallon size with all the trunks present. A shade Crepe is too important not to get a good looking one and the cultivar you want. May your week be full of joy!