I know many vintage machines that will snap the thread if you are sewing without fabric under the needle. So you almost can't chain with them unless you are very, very careful to butt the next piece right up close to the last piece. Usually one stitch without fabric was OK, but the second or third and the thread would break. I learned to stop before going off the fabric, Pull it out a bit to get some tail, then put the next piece under the foot so the needle would come down into the fabric, and then sew. Never sew on and off the fabric.
I was rather surprised the I can sew several stitches between pieces with my Juki 2010 and not have it break the thread. My first brand new sewing machine in 35 years (not counting the LA).
Reminds me of a friend that got a vintage machine, and was complaining about how it kept knotting up and break thread when she started a seam. She never learned about holding the thread tails, as she learned to sew on new machines that didn't require that. When I learned, holding thread tails was a given.