In the case of Supercharge.info this has been raised in its forum discussion; a similar debate was had when V3 started appearing. As I understand it, it's hard to do because it requires changes to the database structure. Previously, a filter for max power was added which allowed V3 to be differentiated from V2, but that won't work for the current V4 stalls which I assume are powered by V3 cabinets.
That said, they managed to add a checkbox for Tesla Only / Tesla + Other EV's so it evidently isn't impossible. It may be that all open-to-all sites are ultimately swapped to V4 stalls so the issue may go away (something similar happened when dual CCS/Type 2 cables started being added to V2 sites - eventually all sites were done so the need to flag it disappeared).
For Tesla it would be easy to update the app instructions but I suspect most folk would prefer to use contactless to initiate a charge (I know I would, based on bitter experience with other charging networks) so the set of people (a) using the Tesla app and (b) reading and acting on the charging etiquette instructions will, no doubt, be pretty small.
