I wouldn't call it much of a stretch. The Skrulls absolutely are representative of the situation at the border. The Trump GOP is demonizing them and making them seem like monsters to the public. Part of why Talos works is that he's not a monster, he's just some guy who happens to look like a goblin to us. And the shapeshifting can be tied back to things like the "red menace" sure, but their whole goal is to find a home and or integrate into existing societies. While the finale does not take place at the border (at least I don't think geographically it does), they are in a place which looks like how most people view the border and facing each other. They may not be fighting on a nations border, but they are on two different sides of a conflict, one wants to stop the violence and figure out how to give the refugees a home and the other is (and does) put people (including children) in cages and using violence to cease immigration efforts.
No this is super contemporary, it's just that there is enough superhero stuff to offset the political message of it.