I'd think it's a double-edged sword.
With HID lighting, the grower can move the ballast out of the grow area - so the heat produced by it becomes irrelevant. And, with an air-cooled hood, the bulk of the heat produced can be immediately whisked away from that area (without ever picking up the smell of cannabis).
However, an LED is - at least in theory - more efficient than either HPS or MH lighting in that more of the electricity is converted to light. Imagine two light sources, each "consuming" 500 watts. One is 21% efficient - IOW, turns 105 of those watts into light - and the other is 56% efficient - turns 280 watts into light. Lights only produce two things... illumination and heat. What isn't converted into light becomes "waste heat." Yes, there is some heat produced by the light itself in a closed area where it reflects and gets absorbed, lol... But a more efficient light source is, by definition, a "less efficient heater" (so to speak) than a less efficient light source.
And... IDK how much heat a typical LED panel's power supply produces. IF it is a significant amount, making that power supply removable/remote (either the manufacturer doing so or the user engaging in a little DiY), that would remove one heat source from the grow room. Also, if a manufacturer chooses to make an LED product that is like an air-cooled hood - with a 6" or 8" "intake" and "exhaust" side intended to be hooked to ducting/fan(s) instead of simply having internal fans and ventilation slots in its case... then much of the waste heat could be immediately removed from the grow room in the same way that it is done with "sealed" air-cooled HID hoods. Such a thing would probably primarily be of interest to those who run larger grows that have multiple, high-wattage lights - but who knows, lol. Many growers that only operate one light per grow space still use CO₂ supplementation - and that requires a closed environment to work well, otherwise one's extra CO₂ is being removed along with the heat. So some of those running smaller grows might also be interested. Err... Due to the fact that, unlike HIDs, if such external fan(s) fail for any reason, the grower will fry more than just his/her plants, lol, I assume that some sort of failsafe would be necessary which would save the LED panel in the event of an overheat. A resettable temperature-activated circuit breaker, maybe. IDK.