If Tideturner is revealed at a location with another unit, and in response to Tideturner's ability you bounce the unit at that location (before the swap resolves), does the location become uncontested momentarily, allowing you to gain a point on your opponent's turn?

Ruling: No, you do not gain a point. Control of the battlefield is never lost during Tideturner's ability resolution. Cleanups (which would check battlefield control) cannot occur during the resolution of a spell or ability.

Sequence:

• Tideturner is revealed and enters the battlefield
• Tideturner's WYPM (When You Play Me) trigger goes on the chain and finalizes (targets are chosen)
• Players can react to the trigger (e.g., play Gust)
• The WYPM trigger resolves completely (the swap happens)
• Only after resolution completes can cleanups occur

Nuances:

• If you Gust the Tideturner itself in response to its trigger, the swap will not happen because Tideturner is no longer on the battlefield when its ability tries to resolve
• Rule 151.3 explicitly states that while a spell or ability is resolving, no other spells or abilities can be finalized on the chain or resolved, including triggered abilities or game effects that would occur as a result of execution
• The swap happens as part of a single resolution, with no opportunity for cleanups or state-based checks in the middle