Wow, if Niantic had an event on the waterfront, and they happened to get city permission so when the sea monster is defeated it triggers a local fireworks display, that could be really interesting - and newsworthy. And no doubt the local cafes and food vendors would be selling out again afterwards too if you can create an event like that....
There could also be fun challenges like "Magikarp invasion!" - 400 Magikarp have invaded Fisherman's Wharf. They need to all be caught in the next hour or else they'll threaten native species.
Create some fun quests and challenges and randomize where they spawn and make them time limited.
I would expect Niantic to have a similar idea in mind for PoGo, but also think they've not fully figured out how they want the mechanics to play out long term, and that might need to happen first.
So it would not be at all surprising if similar stuff found its way into P:Go.