I mean, the article is about the landlord suing Twitter, so the question of how they plan to enforce the terms of the lease seems to have been answered.
Note the landlord here is a big national firm. They're not going to be scared off by having to take things to court, and even beyond the $ at stake, they're pretty highly incentivized not to let customers wriggle out of paying leases just because there'd be lawyers involved in enforcement.
The way you describe it, it sounds like you think he's being smart. I wonder if you and all the others with a similar opinion feel the same about residential tenets who don't pay their rent?
Sure you have a contract but you need to enforce it. So you have to sue which takes time - a lot of time.
Then you “win” but the other party can still not pay, or they could appeal - back to court and even more time.
The landlord has an iron clad contract sure - but Twitter has what they want ($) and the leverage as a result.