Buffs from playing the same civ rumour/leak

According to the latest leak civs may get buffs if you have played them more. The Leaker predicted ages, Himiko and a bunch of other things which suggests it is likely true. Personally I hope this is a mistranslation because with all the talks of ages making it easier to balance civs it would suck if someone had access to an upgrade of a civ simply from having played it before.

If it isn't a mistranslation I hope what they actually mean is that you could choose from a different set of bonuses similar to personas for leaders. Say for example you choose the USA in the modern era, at that stage you could choose from a default say:
USA (colonial)
With a unique settler unit, minutemen and bonuses to growth and military.

Then for buffs they actually mean something like being able to also choose from say:

USA (WW2)
With Sherman tanks and/or P-51s and bonuses to political influence and military.

USA (Hollywood)
With a unique musician unit, film studios and bonuses to economics and culture.

These are not the best names or necessarily the best UU/UB just what I hope they actually mean if the leaker is right and not that you play enough of USA then you play USA+1.