On the live interview Microsoft and Asobo streamed on August 13th, the subject of helicopters came out (which is starting to become something normal – meaning there is more awareness and concern about this type of aircraft) and a couple of points were mentioned.
I’m excited to see what helo models they decide to work on and what level of fidelity they’ll be. I expect that they’ll be on par with the default fixed wing but we can hope for more.
Great news, and this makes perfect business sense for MS & Asobo: give people a taste of helicopters for free and then have a paid DLC for those that want to go further.
Personally I would be very happy to put my hand in my pocket for some quality helicopter DLC. Very glad they are talking about getting the flight model for helicopters right, and I’m especially excited that they are talking about putting in extensive heliports. Combine this with VR support and this is looking like it could be a really compelling package 
I hope with the helicopter support they will add also one or two free helicopters, so people could test helicopters before buying anything.
The sim comes bundled with a few aircrafts, that would seem normal to have some helicopters in the base price.
I also hope enough good third party developers (dreamfoil, are you around ? ^^) will be interested in MSFS 2020 to make great helicopters.
A few helicopter developers are interested in the sim, yes. I’ve been talking to, at least 4 developers that are taking a look at it and are interested in eventually doing products for the sim.