I worked at an upholstery factory for about 5 years a while back. We only did home furniture but the concepts are the same. the only difference really is how the covers are attached. Staples on sofas and chairs and hog rings on metal-framed auto seats. I was an upholsterer there. We got all of our pieces as kits. So, we'd pull the sewn covers out of the bin and put them on the piece. I never learned the cutting or sewing side of the process. Wishing now that I would have. I would have just made my own covers..
That loose stitching may never unravel or get worse but it doesn't look good and if it does unravel or open up, the cover would have to come back off. Gotta make sure it's right the first time!