Android 14 Beta 1 added a new developer option, ENABLE_SMARTSPACE_DEFAULT_DATE_REMOVED, and it does what it says it does: remove the default date on the home screen.
No, this flag does NOTÂ completely removes the At a Glance widget, since all other notifications (a timer, connected devices, calendar events, etc.) will still show up in that space. This means that you still won’t be able to place anything else in its place.