I find it hard to believe that bandwidth would be lower. In our Dahua HDCVI 2.0 Test, camera bandwidth was relatively high, with a lot of the CVI cameras running over 4 Mb/s in the daytime, higher than most IP cameas in the same scene.
We don't have them listed in that chart, but a 900TVL camera in that scene usually runs well under 1 Mb/s. This is assuming average 28 quantization, VBR, no cap.
It's also impossible to make a blanket "A is lower than B" statement, since the scene, compression, brightness, sharpness, camera performance, and a lot of other variables impact it. Do you know what cameras/DVRs they were talking about, specifically?
The good news for remote viewing is that pretty much all of their CVI DVRs will send a secondary stream, up to VGA resolution. So you wouldn't necessarily be losing anything on the remote view side by switching, and you'd gain higher resolution recorded video.