Auto-night mode doesn't switch back to light theme
Auto-night mode does not work as intended when set to either system default, or adaptive, or schduled by time, or scheduled by sunrise/sunset time. In both cases Telegram switch to dark mode, following…
However, this isn’t really a privacy issue for the app to solve, as it allows you to link to a user with arbitrary text. A person can just change the mention link from the username to their real name pretty easily.
If anything, having the option for a user to set the default mention text (either to something specific or to allow to use other user’s contact names for that user) for a specific group is a convenience feature (and one I would very much like to see added)