As someone who uses ellipsis often, but certainly never with sarcasm in mind, this was fascinating and shocking to me to learn this. I also want to appreciate @bluestein’s graceful response to the misunderstanding.
I wonder if it has anything to do with the joke format, "that's a nice tie... not." which sets up the victim and then delivers a gut punch. Perhaps it has conditioned a skepticism towards ellipses.
I didn't interpret your comment as bad will, but I'm glad this opened an interesting conversation about language!
PS. Honestly also both fascinated and shocked to learn about the new use that ellipsis is finding. Color me surprised.-