It's weird to bring the case so long after the alleged breach, but as long as the breach of contract statute of limitations is five years, they should be fine. I assume that the timing is intended to pressure Tesla to settle so as to avoid negative publicity as their cars start rolling out.
Tesla smartly removed the case to federal court. Just based on reading the Complaint and Answer, I think Tesla has a good defense to this case. The "contract" they signed is really just an agreement to enter into a contract/lease. These are pretty hard to enforce. To the extent that the developer spent hard money in anticipation of Tesla signing a lease, they may be entitled to recovery of that under the concept of promissory estoppel, but otherwise I don't see any big exposure for Tesla. They can settle cheap, but I assume the developer is counting on home court advantage to pressure Tesla to pay more than the case is worth.