Those that hate Trek being shown in 4:3 so much need to learn how to zoom or stretch the image on their widescreen televisions until it fills the entire screen. Problem solved.
That's only the solution or choice proposal of those who don't care.
Zooming up the image to fill the screen to have an acceptable result would only work with those DS9 and VOY episodes that were "protected" for widescreen.
And since that protection frame is usually cropping more at the bottom than the top you'd need a flat screen where you could manually adjust the height of the extraction frame.
(If CBS goes for DS9 and VOY in 4:3 they should at least provide a test image for zoom extraction (height level) of the widescreen "protected" episodes.
Somebody please tell them, thanks!)
But for close-up shots and the like a simple zoom would yield horrible results, namely to cut off actor's heads and chins.
In such close-up shots the use of the undisclosed areas left and right on the camera negatives would become mandatory for a palatable 16:9 or a rather cautious 15:9 presentation.