The Twister pattern was also published in the 60s and 70s, which were probably 'inspired' by a much earlier pattern.
There are many resources that have documented the publishing of early patterns like Jinny Beyer's book called The Quilter's Album of Patchwork Patterns which shows over 5000 patterns and their different names that they were known as.
These blocks are in the public domain but in today's busy world, 'usually', the 'average' quilter/sewer isn't interested in finding a block she likes, drafting the pattern to the size she wants, figuring out what fabric is required and then putting it all together in a design that she finds pleasing. It is easier to shop and buy a currently published pattern, follow the directions and make the quilt even though the actual block/pattern has been around for hundreds of years. The 'copyright' applies to the written instructions and information that the current writer has used.
Those of us that have been sewing for a very long time have seen many patterns 'recycled'. I agree that there is lots of confusion with many blocks/patterns being called 'original' when in actuality the only thing 'original' is the newer fabrics that are used and the rewriting of instructions which may, currently, make it easier to understand and make. This 'newer' copyrighted info makes today's economics of 'quilting' a multimillion dollar business.