So i was thinking about the mega teaser and i remembered something. Recently, Game Freak has been playing around with the past and time travel. So the theory is that there won't be Mega Evolution in Legends Z-A but forms from the past. Just to support this, this is Mega Aerodactyl's Ultra Moon entry: "Mega Evolution awakened some dormant genes, bringing back the sharp rocks that once covered Aerodactyl’s entire body." Yes, Aerodactyl is a fossil Pokemon but the "dormant genes" has me wondering whether Aerodactyl is the only Pokemon that gets its dormant genes awakened by Mega evolution. Maybe the trailer was hinting at something to do with Battle Bond because i doubt that Game Freak would leave the ability out, especially in a remake of the generation it was introduced in.
Let me know what you think, Have a blessed day.