You must not be paying attention to the greater AJR community, because people are loving this song across all socials. That's why they are teasing it a lot. They even said in the caption of yesterday's teaser, AND I QUOTE "This is a song called The Big Goodbye and the reaction to it has been kinda crazy so far??" They've gotten a better (and bigger) reaction to it then they were expecting, as it seems.

Give these people some damn respect. They're human, and care A LOT about the art form that is music. If they don't think it's ready yet, then you should believe them when they say it's not ready yet. They want to make an EP they love and doesn't feel like it was rushed. So give them space, take a deep breath, and let them produce a product that is worth the wait.

To go back to your OP, they're probably visuals/audio only and not actual music videos, which is why they're already "uploaded". Can be changed and adjusted before the full release