All Mega Evolutions will be retconned out of existence, except for Mega Lucario
However, it will be retconned into being a permanent evolution of Lucario. You'll receive a level 100 M-Lucario as a gift for catching your first Pokemon, and it will have maximised IVs and 252 EVs in every stat (unique to the Lucario line), and it will have the nature 'Proud', which gives a 10% bonus to all stats with no drawbacks, also unique to Lucario.
Oh, the secret to Rockruff and the starters? They also evolve into Lucario, but will have an additional 3rd type based on their own typing.
At any point all of your Pokemon are KO'd, one final secret -- YOU will transform into a Lucario, and your opponents will be unable to attack.
