Thanks everyone. I called the concierge after learning my flight (the last flight of the day) would be late 2 hours and 25 minutes. I'm now scheduled to land at 3:05am.

The concierge was kind enough to get a hold of an agent at the airport. A notification was just made and vouchers are being given to everyone.

SE's get $15. Others get $10.

Edit: My meal voucher has the following reason: Delay XXXX where XXXX represents the flight number over 2 hrs

So based on the comments above, although 4 hours may be the guideline, there are cases where it's given for a 2+ hour delay.