I'm sorry, I don't think I got that. I don't find a mailing list called itertools-ideas. Do you mean this should go to python-ideas? If so, I'm sorry for bothering python-dev, and I'll move this to python-ideas.
I just read "The python-ideas list is for discussing more speculative design ideas" (https://www.python.org/community/lists/) as meaning discussing ideas for significant design changes, and not for adding a small function.