> "Tidal forces cause a lot of stress on celestial bodies",
Correct
> but not with the Earth-Moon system because the Moon's "rotational energy was spent".
Not now. But the Moon is still stretched tidally (and permanently in that position)
It causes a lot of stress when the tidal pull happens while the body rotates (w.r.t their main "puller" - the Moon rotates, but not relative to the Earth)
And this pulling/stretching is what caused the Moon to stop rotating
Maybe Wikipedia explains it better https://en.wikipedia.org/wiki/Tidal_locking
Taken as a whole, I read the comment as possibly along the lines of "This seems reasonable (or obvious) - you end up with dead lifeless geologically inert celestial bodies like the moon if you take away the stress of tidal forces / (varying) gravitational pull", as an example to contrast/compare against.
I'm not disputing that the Moon is tidally locked, just the consequences in terms of tidal forces. But perhaps the issue (and maybe err) is in confusing rotational energy with orbital energy and the relationship to tidal forces.