The technician where I just bought my new machine told me about the thread thing. I hadn't known that either.
In addition....he said the same thing about the bobbin. It has a very sharp razor like place that when you pull the thread out backwards when you just take out the bobbin, it will build up fuzz and make the bobbin not perform properly. Instead, you should remove the bobbin, snip the thread, then pull it out as it would come out when it is sewing. Huh...who knew??