Sure, they’ll keep revising 5e, while making sure the absolute smallest number of 5e books become “legacy” in the process.
But the people who are making most of the D&D related content are not new to D&D. They remember past editions. What’s more, past edition works are available via DMsGuild. They aren’t going to try to change what a new numbered edition means. If they call it something new, it will use a different nomenclature from past new editions, because it isn’t the same type of thing, and because they don’t want to screw with sales by giving people like Mike Shea and the most popular actual play games, etc, to magnify controversy over a confusing name change.