Isn't so called "mens" categories actually open? The "protected" categories exist because able-bodied men dominate (in the top levels).

After reading the article I'm not clear whether this 'open' category will be a new, separate category, or whether it will replace the 'mens' category (which may be the simpler and more pragmatic approach unless there are complaints).

Pretty clear that it will replace the men's category.

What a great idea. Allow un-drugged, "natural" atheletes as a class, and allow "open" for those who choose to use chemicals or whatever to enhance performance. The rules on "cyber enhancements" should be good for centuries of pleasant and ultimately meaningless flame war.