I actually think that the Bug-Type Pokémon are the ones who First Impression is most confusing for.
- Farfetch'd is based off the Japanese expressions "a duck comes bearing onions", which is used when referring to something unexpected but good.
- Falinks looks like a long Pokémon with one body, but is in fact six little dudes working together, which catches opponents off-guard.
- Trapinch "makes a conical pit in desert sand and lies in wait at the bottom for prey to come tumbling down" (Gen IV and V dex entry), which is certainly an element of surprise.
- Axew: "They play with each other by knocking their large tusks together. Their tusks break sometimes, but they grow back so quickly that it isn't a concern." (Shield) makes more sense with the Japanese name of Head On Assault, where they rush into battle with their heads without hesitation (hence priority) because their tusks grow back should they break.
And then finally we have Durant and Golisopod. Durant makes some level of sense because it has huge mandibles, a high speed stat, and Hustle, so it makes sense for one to charge into battle head-first immediately after being sent out, but I would argue no more sense than some Pokémon who don't learn the move besides it being STAB. On the other hand, Golisopod has very little connection to the move itself. The closest it comes to a justfication is "It will do anything to win, taking advantage of every opening and finishing opponents off with the small claws on its front legs." (Sword) but that honestly sounds more like a justification for Sucker Punch. Obviously the attack has good synergy with Emergency Exit, but that's gameplay justification rather than flavour.
I think most of the oddness surrounding it stems from the question of why the heck it's Bug-Type to begin with. Head On Assault is a name you would expect to see on a Fighting- or Normal-Type move, and First Impression is probably Dark-Type more than anything else thematically. I think it's cool that it is Bug-Type because it helps make it a better-rounded type, but it brings up some weird flavour quirks when there's nothing inherently bug-related about it.