I don't see a good reason to discontinue the S and X. Doing so just means more gas guzzling big SUVs and sports cars will get sold. By all means stop updating them, but even if Tesla waits another 5 years to do a big S/X refresh, then thats a long period of time in which they are not sidetracked by that model.
People who already own a 3 or a Y, but come into more money / bigger family should have an option to stick with tesla.
Plus I think all companies benefit from having a low volume high price product in the lineup. That means new tech, new batteries, new ideas can be trialed on the S or X and then ported over to the main sellers once they are proven.
I doubt much board-level time was spent on the S or X from 2015-2019.
Ya, more Tesla's in more segments, not less.