Hmm are there even enough levels for them to reach that goal?

Nope.. Adding up all the tiers up totals a maximum of $9,550,000, for a total of 56k watches.

Interesting that they didn't design this to break their 10.2M record of the first campaign. I'd bet they are going to increase the slots or or announce addons for the pledges to go for it. At this rate they are going to be sold out in a couple hours, if that.

They posted an update saying they're bumping the 2nd single-watch tier by 10k, and will add a new single-watch tier with a later ship date when that sells out.

I'm sure someone at Kickstarter would be happy to immediately add a new tier for them if they max out.

They should be able to do that themselves (I've seen a lot of projects adding tiers in the middle of campaigns, you can't remove/change existing tiers).

Kickstarter shouldn't be able to add new tiers by themselves, as they have no say what the price/rewards should be. The current tiers are likely (hopefully) carefully planned based on their manufacturing plans and how many watches they can fulfill in the schedule given.