Not necessarily. Assuming the new phones would get that feature, it's not like the initial 15.0 version has to have that. The phones could easily ship with 5.1, or it be a feature activated in the future like 5.2 or 5.3 etc. Plenty of new iPhone features don't show up in betas every year.
That being said, I wouldn't ever expect an iPhone with an AOD. Apple already has one they'd rather sell you: The Apple Watch.