Why not just display test explorer unconditionally.
Benefits:

• Improved discoverability of Testing as a feature in Python Extension
• Improved discoverability for novice users of VS Code (those not used to VSC commands).
• Also, provides a better work flow:
  • Anyone wanting to configure tests, doesn't need to select commands..
  • I.e. user wants the UI, but they need to use commands to get started..
  • Why not just display an empty test explorer, then users know they need to configure something (all from one screen).
• Allows extension to refresh/display the test explorer as soon as tests are configured (Automatically display the test explorer icon when configuring/discovering tests #4828)