Play tideturner get gust

Yes — provided Tideturner is at a battlefield when Gust is cast, bouncing it makes the swap do nothing at all.

Tideturner's "When you play me" trigger finalizes on the Chain, which puts the game in a Closed State, so a [Reaction] spell like Gust is legal. Gust resolves first and returns Tideturner to hand; then when the trigger tries to resolve it needs "my original location," which is now null because Tideturner is in hand — a non-board zone. So neither Tideturner nor the chosen unit moves, and Tideturner stays in hand (FAQ 8272).

The one condition: Gust only returns "a unit at a battlefield with 3 might or less." Tideturner is 2 might, so it's a legal target only if you played it to a battlefield — if you played it to your Base, Gust can't touch it and the swap happens normally.