A 27-inch screen these days is 2560 x 1440 pixels so that is 3,686,400 pixels. To take into account sample errors, you want at least 3X for that, or 11,059,200 pixels, adjust for 16:9 to 3:2 ratios and that drives you to 13,107,200 Give yourself a little crop room and 16 MP seems about perfect. If you want 4X oversampling then you get 17,476,267 pixels, give yourself some cropping area and 24 MP is close to perfect. Even for on screen use 24MP is not too much especially when very high resolution screens start to appear. That 27-inch at 260 DPI would be 20 MP. Over sample some and you are well north of needing 50+ MP in the camera.
Why are you talking of oversampling? "Sample errors" is just another way of saying noise, unless I don't understand. A higher MP sensor has smaller photosites, and more noise...so your oversampling is just a software approximation of a lower resolution and more sensitive imaging sensor...so you actually want a lower resolution camera after all.
Oversample for the same reason you do in music. You record at 44 kHz or 96 kHz and play back at 20 kHz. The extra pixels allow you to better image fine content and have a better image.
You probably mean pixel-binning, where several noisier photosites can be read/combined to represent a pixel than a single larger photosite, the result is an image with lesser noise and better DR than their larger counterparts. And sensors specifically designed for pixel-binning uses a color array different from the regular Bayer. Nokia's 41MP sensor, AFAIK, still uses a Bayer configuration but reads the photsites differently. By 2016, I expect APS-C/DX sensors with BSI CMOS sensors with 96 to 160 MPs but will only output 20 to 36 MPs images.