I try not to draw any comparisons between Tulsa and Phoenix since the airspace is so vastly different.
Probably beyond the interest of most here but....
Yes, Phoenix is a lot busier than Tulsa. Phoenix is Class B airspace, think Chicago, Atlanta, Dallas-Ft Worth, Los Angeles. Requirements to fly there are more strict than places like Tulsa (Class C airspace).
I do know that all of the LEO helicopters here have FLIR, so that gives them a "stealth" mode so to speak. Maybe that's one of the new features TPD has. For several years the quiet option was the Hughes/MD 500 NOTAR, but they all moved to larger helicopters for search and rescue operations.
NOTAR was a no tail rotor system which is quieter than having a tail rotor. Maybe a bit of stealth. Still difficult to hide the main rotor sound unless you are in Hollywood.
https://en.wikipedia.org/wiki/NOTARFLIR (Forward Looking InfraRed) is a camera system, kind of, sort of like night vision. Nothing to do with quiet. It's been around for a while.
ADS-B not being a requirement makes sense. You can't make it one size fits all. But a new aircraft, I would think, has it built in, and from what I have read it's an automatic system.
ADS-B is a requirement, just not everywhere. Getting a temporary exception is probably easier in Tulsa than some place like Phoenix, etc. Most airplanes have been converted to be equipped with ADS-B Out (You transmit your info) and I cannot imagine a factory built airplane without it. Maybe some homebuilts won't have it, depending on where they want to fly.
ADS-B allows equipped aircraft and ground vehicles to broadcast their identification, position, altitude and velocity to other aircraft and ATC. This is called ADS-B Out. Being able to receive this information is known as ADS-B In.
"ADS-B Out is an evolutionary step in communication between the aircraft and other airspace consumers. Current transponders enable ATC and other aircraft to know your aircraft's relative position and altitude. ADS-B adds important information to help project and prevent traffic conflicts by estimating intent," explained Jake Biggs, Textron Aviation's aftermarket engineering manager.
"ADS-B requires extremely accurate, three-dimensional position reporting to reduce reliance on ground-based radar to allow tighter separation standards. The advantage to all airspace users is an extremely accurate understanding of traffic and where it is going," Biggs said.
https://txtav.com/en/journey/articles/articles/adsb-out-explainedIdentification will include the N-Number and type of aircraft (Cessna 150, Beech Baron, Lear Jet....) so the Air Traffic Controllers will have a good idea of the capabilities of your aircraft. I believe it shows up automatically on the ATC radar screen rather than having the controllers manually enter the info. ATC in Tulsa still assigns a Squawk code for the regular transponder when you contact Tulsa Approach Control if you are just flying around. If you are on a route, talking with controllers, you will already have a squawk code.
ADS-B doesn't work without WAAS (fancy, more accurate than your car) GPS.