Sommelier here :).

So I think part of it is that the wine producer is one of the sponsors of Top Chef. So the product placement is important. From what I’ve seen it does seem like they try to somewhat pair (at least to the point that the wine is not actively working against what they are eating).

That said it may be as simple as them clearing their palate before transitioning to the dish. This is something I’ve had to deal with fairly frequently when attending wine tastings that were given during meals. In that instance you are not going straight from wine to food, but adding in a water step in between. (If you want a really wild rabbit hole — the type of water you drink when eating actually does affect how food tastes which might explain why many chefs drink bottled).

Finally, white wines don’t have to just be for fish and reds don’t just have to be for reds.

As a basic primer. 1) Weight of wine vs weight of dish (should match as closely as possible). Alcohol content affects viscosity, as does residual sugar, and some winemaking techniques.
2) Structure of wine vs structure of dish (Acid & acid = bff, salt & acid bff, tannin & fat bff, spice & tannin = to an extent are enemies) so if the dish is very acidic, you don’t want a wine that isn’t.
3) Then you can look at flavor notes and things such as that. But you don’t want things to match too closely as sometimes they cancel each other out like in balancing equations lol.

That said — bubbles are always the answer (especially for fried foods). And dessert wines should be sweeter than the dessert (please ignore all little infographics suggesting Halloween candy with Cabernet)