Seems HN is does not have expertise in this and who holds the cards in the current market in SF. The lease previously negotiated by the past regime has little relevance as Twitter is currently occupying less than 50% of the floor space. The landlord has to either accept lower payment, or look for a new tenant and Twitter moves to Austin. Given the current environment in SF, it's likely a new tenant won't be found for…
What a completely bizarre interpretation of contract law. Lessors may be in a bind after the lease expires, but during the term of the lease they are entitled to its terms. Nobody can simply stop performing the terms of a lease, outside of bankruptcy.
That being said, I would bet the article is just lazy journalists trolling for clicks as usual.