I've been saying this for over 3 decades that I've been flying out of SNA, as it is my home airport since I was 9 years old. SNA should have built a bridge over Bristol street as an overrun to 20R to lengthen the runway another 2200'. That would have allowed the B787 access on those long thin routes. LAX has multiple tunnels with airplanes taxing over them. When you exit the 105 freeway and drive towards LAX, the first thing they do is route you under a tunnel with 25L/R above you. That would have made 20R 8000' long. The airports property extends all the way past the golf course which would give them another quarter mile of breathing room after the runway ends. Alas, the NIMBY's would never have allowed it to happen.
Expanding SNA's runway was probably never a serious consideration when Orange County sought to redevelop Marine Corps Air Station El Toro into a fully capable international airport. Of course, hindsight is always 20/20, but I have to think that an El Toro commercial airport probably would have become a white elephant if not in the Great Recession then certainly now. A centrally located facility in Irvine really is the perfect location for Orange County's airport. Those in the northwestern fringes of Orange County that find traffic to be a hindrance to/from SNA can easily use LGB, which offers just as wonderful of an airport experience as SNA does - plus, thanks to the much longer runway, nonstop services to BOS, HNL and JFK (at least this was the case before the pandemic, and hopefully it will be afterwards as well). I'm sure just like here in LA many OC travelers know that JetBlue offers quite a bit of service from the beautiful, hassle free LGB airport. Those in the northeastern fringes of Orange County that find traffic to be a hindrance to/from SNA can easily use ONT, which more or less also offers just as wonderful of an airport experience as LGB and SNA - plus, thanks to the much longer runways available, nonstop services to JFK and even Asia (at least this was the case before the pandemic, and hopefully it will be afterwards as well). Those in southern Orange County likely wouldn't experience nearly as much traffic to/from SNA, but could probably use SAN if SNA doesn't have the flight options they want and getting to LAX is too painful.
I was at a political fundraiser in 2018 at Pelican Hill the week before the election where Dana Rhoerbacher was attempting to hang on(there was no chance of that with his Russia ties). Dana stood up at the house and told a row of semi billionaires that he wrote a letter to the CEO of Jetblue, informing him that a minor tweak to the design of the A320 would reduce its noise foot print tremendously. I nearly spit out my wine. Not one person in that room spoke up about Jetblue never having flown into SNA. I don't think anyone in that room even knew that fact. SNA has a tremendous amount of potential, but the multi billionaires that live under its departure path, wield tremendous amounts of power and influence over Newport Beach's city council and the county board of commissioners.
Are "semi billionaires" likely to use B6, though? If those types of people even do fly commercial, chances are they would gravitate to a "legacy" carrier with perks like lounges and robust schedules. The advent of Mint may have changed the appeal of B6 somewhat, but I think we can all agree as soon as B6 has the A220 they will finally add service to SNA. In the meantime, LGB being east of Long Beach makes that airport quite convenient for Orange County travelers; never mind the resumption of service to ONT and the success of Mint from nearby LAX and SAN...
The vote for SNA to have a complete redesign was postponed 2 weeks ago due to COVID. They've been having meetings about it for years. If you think for one second plans haven't already been decided on how SNA will look for the next 40 years, you don't understand how deals are made behind closed doors. I know this for a fact, more than 2 billionaires that own FBO's at other airports and want access to SNA, are throwing money in every politicians direction to win the bid. They want to park their $50 million gulfstreams in a hangar, and they soon will. It costs $20,000 per month to park a G650 at ACI JET. My cessna costs $140 per month. Do the math. It's obvious where this is headed. The wealthy have the money, the politicians are more than willing to take it from them. Theres over about $1.5 Billion worth of aircraft just sitting on the ramp, in the elements, on a daily basis. Meanwhile, cessna's have 3 rows of shaded parking.
Whatever happens, construction probably won't begin until the end of the decade. After the vote finally occurs, the environmental studies must be completed, the lawsuits and counter lawsuits must be settled, THEN construction will begin. My guess is towards the end of the decade.
EYW and HHH have both recently exploded in popularity after runway extensions - and those airports have even shorter runways than SNA! I would not be surprised to see a very modest runway extension at SNA - so long as carriers like HA and WN could fly to Hawaii with a viable payload, that would probably be enough. Also, we have yet to see the impact of the A220 on SNA. Maybe B6 could even operate something like BOS/JFK-SNA-Hawaii with HA codeshare on this type from the current runway?