The oft-mentioned was a speculation and what do you think about it. HTC’s upcoming Aero 9 aka One A9 flagship will run Android Marshmallow version 6.0 or else coming with Android 5.1.1 Lollipop on-board. Earlier it was spotted on Geekbench booting Android Lollipop, but today according to a prominent HTC leaker @LlabTooFeR, revealed that it will be launched in October-November time frame, which is of-course in line with earlier rumors.
For now, nothing has become official and confirmed as well. So take this news report with a grain of salt. However, the Taiwanese firm has scheduled a press event on September 29th. Expected to witness the One A9 (Aero) flagship launch alongside the Butterfly 3 smartphone. Stay tuned!