"All rational beings will be moral, but this paper worries me that AI, while efficient, may not end up being rational. Maybe it's worth worrying about."

Why not argue for this directly, instead of making a much stronger claim ("may not" vs "very unlikely")? If you make a claim that's too strong, that might lead people to dismiss you instead of thinking that a weaker version of the claim could still be valid. Or they could notice holes in your claimed position and be too busy trying to think of attacks to have the thoughts that you're hoping for.

(But take this advice with a big grain of salt since I have little idea how academic philosophy works in practice.)