The article suggests that, since both companies are founded by Stanford grads, they have similar social networks and so are drawing on the same pool of talent.

I have no idea if that is true or not. My two cents are, "why do you think its just Uber?" Its cheap to add filters, maybe they have them for Google, Apple, Facebook, etc. Maybe having one for direct competitors like WhatsApp is a bit much.

Snapchat responded saying that its not just Uber.

They're targeting any company that fits into their potential talent pool. Its easy and cheap, the hardest part being the artwork.

We also have no idea where they're targeting, since the geofilters are a call to Snapchat's servers.