Considering what new defender does, should I uninstall MBAE and NVT-ERP befor update to 1709, for which I got notification today?
Well it probably wouldn't hurt to do that, but if you can just turn off active protection for both than that would probably work just as well with less effort. Some people uninstall their protection for windows updates, some turn them off and some leave protection on. I just turn them off and have never had a problem yet. No one stop solution for everyone, to be safe just turn them off.
Well balanced assessment. I just turn MBAE, VS protection off, those are the apps I use. Not Windows Defender as I don't think it will interfere with Windows Upgrades. I would uninstall a third party AV though as I found that disabling those is not enough. Bitdefender for example I found it to be a pain with installations in general. But that is me and more experienced user may not have the same problems that I had.
FWIW, when I had a third party AV, I always uninstalled them before a major upgrade for Windows 10 (or any old Windows, for the matter). I'm not familiar with the security apps that you mention but well, if I were you I would remove them for upgrading purposes, just to be in the safe side.