Clarification - Yes, using the wheel to zoom in/out on the Navmap and TDC has always worked in stock and GWX, but it never worked when you are PAUSED (unlike everything else on the Navmap, which worked just fine when you paused the game, so I think it was an oversight by the developers). That last tip above, will get it to work when PAUSED as well (Coward that I am, I like to plan and draw my attack routes while the targets aren't moving around)
In both GWX and stock, the UZO/Binoculars only had one fixed magnification and never zoomed (Apparently, in real life, the UZO only had one level of magnification). Anvart's change lets you zoom with it if you want, but leaves you free to just use the one level if you prefer. By the way, Anvart's change lets you use the Ctrl+Mousewheel to zoom in further with the deck gun too.