backlit keyboard on refresh model

Highly unlikely that they will remove it with a "minor" update.

 

blocks speaker sound

I don't own the version without the backlit keyboard, but I highly doubt the difference is worth removing the back lighting. That is, I don't believe people would be complaining if the original version also had a backlit keyboard. Maybe the ventilation of speakers could be made better, but not remove the backlight.

eats battery

I haven't tried testing a battery cycle with the backlight and with out it, so I am unsure as to how much power consumption it has. But it can be turned to lower outputs and even off, to which I would hope brings its consumption down to nothing.

increases weight

A few tiny LED's and the thin circuitry along with it? Has to be a small amount of weight! I would like to know the difference on that one.