Yes, there's one dialogue that talks about that, but if the Spires always give the power to summon Edicts, and your Edicts are already powerful enough to be a threat to Kyros (the ending slides make this clear), then it isn't particularly smart to basically encourage you to take them all.
Now, Kyros clearly wanted the Peace to end and for the Archons to fight it out, since it was clear to everyone the two armies could not continue working together for long. And at least after you took the Hall, or maybe before, Kyros counted you among them, such that even if you buttfuck the other two archons Kyros is pretty OK with this. The question is whether Kyros also expected and blessed your ability to learn to cast Edicts - which can't really be parsed out because it's never really explained in a logically coherent way. Can anybody claim the Spires and earn powers as you have? The game sometimes hints that no, you must be SPESHUL SNOWFLAKE, but doesn't even bother to explain it and nobody really asks the question. What is an Edict, and why would the ability to cast Edicts be linked to the Spires? Who knows? Why do you learn Edicts by cancelling them? Who knows? Once you try and fail to write an Edict, there is speculation that Kyros might also have acquired Edict powers through Spires and that over time you learn enough to dissociate your voice, but then is it your casting two Kyros edicts that gives you the power to subsequently learn Edicts? The game talks about how most people die within a few years of casting/cancelling Edicts, so is it simply that there's SO MUCH MAGIC and everyone dies but you are special STRONK and you can handle it?
(Actually, this is probably close to the mark, since there's a lot of talk about how there are people born with the power to grow into Archon-level greatness. The really interesting bit in this part of the lore is how renown and legend become self-fulfilling prophecies, turning those spoken about into ever more powerful and monstrous beings - it's a pity this aspect wasn't played up more often, and instead you just gather macguffins like it's NWN1 and all you ever experience is the power fantasy of GROW STRONK.)
As long as you have Kyros' Edicts as the only special macguffin in the game, you have a very nice, compact, interesting political situation set up where the motivation of all parties makes sense. Once the Spires come into it and all the "cuz ur special" stuff through the back door, I think there's a lot of muddying going on.