Can Teemo Strategist still reveal cards after being returned to hand by Gust during combat?

Ruling: Yes, Teemo Strategist still reveals the top 5 cards even after being returned to hand by Gust, though he won't deal any damage.

Nuances:

• You lose control of the battlefield once you have no units there, even during showdown
• The rule about control not changing during showdown only means you don't lose control just because the battlefield becomes contested
• If you reveal a unit (like Nocturne) that could be played to the battlefield, you cannot play it there because you no longer control that battlefield