At the same time, we see a lot that rather than being the emotionless purely logic-driven creatures that they claim to be, Vulcans are still emotional, often making emotional decisions by pretending that it would be more logical to do one thing than another.

Sarek still wound up with Amanda, and cared for her, even if he went with the emotionless mask.

If Uhura’s theorizing was correct, an emotionless Spock would have probably been involved in the ensemble songs the same as always, but would by definition be incapable of experiencing “emotions […] so heightened that words won’t suffice”. So it is unlikely that he would have found himself belting out a solo about anything.

Although by that logic, even if Spock was emotionless, he just had to reach a point where words were no longer sufficient in conveying the meaning that he wished, and as such, he may still have sung a solo.