No and no.
The devs have explained that knowing the AI's ethos and personality is absolutely necessary from a gameplay perspective for the player. They likened it to other Grand Strategy Games - you know right away that France, for example, is going to try and blob in Europe, Genoa and Hansa are going to try and dominate trade, Spain and Portugal are gonna colonize rapidly, etc. In Stellaris, having no idea whatsoever what a new AI was like proved to be a massive hindrance to the player, both in gameplay and in enjoyment.
On the fluff side, I also disagree. You say the player learns 'precisely and instantly' what an AI is like, but I would argue that's completely wrong. You forget that contact involves a large research project before communications are established - that is the gradual process, involving both learning how to communicate but also learning enough about them to communicate effectively. It makes perfect sense that once you've finished that project you know enough about them to understand their basic personality and culture.
