Only simple AI support.
When AI is capable of promoting, there is a 20% chance it will select one of the available totally python promotion instead of the one it wanted.
In other words, there is a chance it may end up with a promotion that it does not want intead

P.S.
Available means it met the requirements
On the good side
A)The only promotion that the AI may not understand is Mentor, which the unit has to stay in city for the benefits
B) Most of the benefits, the AI do not need to understand how they work, so long as they have it, it is beneficial as they will automatically proc upon combat result.
For instance, Rally summons units on the spot when the unit wins a combat.
The AI does not need to know this, it will just be surprised, "Hey free unit"
Or Divine Strength which adds 2 Base Combat Strength.
AI will just see its strength goes up without knowing why, but who cares

Once chosen, the AI benefits from it, regardless of situation.
2 extra strength will be nice for all units.
Of course, you won't expect AI to be smart enough to mass produce dumb useless units with Retribution promotion just to bomb at you.
C) Those with XML benefits, such as SiegeBreaker, Raider and Scavenger, there is no AI support added.
SiegeBreaker reduces city defense when the unit kills a victim in a defended city.
Thus, with the added city attack XML effect, chances are AI will select it on a unit that is supposed to attack cities anyway.
It is just that AI may view it as less useful than a normal city raider I promotion, since the XML isn't that high.
Of course, you can simply add it into the AI promotion list.
D) Instant heal has unique AI support.
AI will choose/force to choose it when it is dying.
Overwrites all others.
Again, don't expect AI to cheat like humans, storing 10 promotions to use them in battles.
E) Damage inflicted by python are no longer fatal.
So a unit with Frenzy will not kill itself when it kills another unit.
Or a dying modern armor will not kill itself when killing a warrior with Retribution.
In a sense, it is for merging codes, so that other promos like Last Wish will not be bypassed as units are killed unknowingly.
In another sense, it is also for the AI, as it seems perfectly alright for a dying modern armor to whack a warrior, but it does not know it will die as well in the process.