Is it real that Apple is going to stop the development on Airport series?
Apple has made not made an official announcement regarding their future plans for the AirPort routers.
All we know at this time is that the AirPort Express, AirPort Extreme and AirPort Time Capsule are still offered by Apple, but the two most recent products.....the AirPort Extreme and AirPort Time Capsule were introduced almost 5 years ago, and there have been no changes to the hardware on these products since they were introduced.
You might not be aware that Apple recently began to sell the Linksys Velop Mesh Wi-Fi system in their stores and online. This may or may not be a hint regarding Apple's future plans.