Good speech can and sometimes should be emotional.
Adrenaline, cortisol, and other hormones can and should stimulate our bodies and brains when we discuss subjects that matter.
I love it when my SO stands up to emphasize her words with gestures. Her voice rises with the conviction that her point is relevant and important.
Usually it is. If it isn’t, she almost always easily moves on. Even if she doesn’t, I still love it.
I know she talks with feeling because the subject matters, not because her ego or “identity” is emotionally invested (though even that can be good).
When people care about what they are saying, their bodies resonate with feeling.
IMO, it’s a mistake to try too hard to control that or hide that. Emotions like that stimulate the mind/brain and make us smarter.