I honestly hope that they keep an eye on sites like this, and I think it possible that some do indeed. I surely would, if I were them. I think it would be a very important opportunity to see what fans think/want, and so an important guide for assessing their decisions.
But I'm quite sure that they know, one way or the other, that there are a lot of fans waiting for DmC2. However, we must also take into consideration that there are fans who absolutely don't want it, and want DMC5 instead. They must trade very carefully, because with making the reboot and with some poor choices in communicating about it, they unwillingly split the fanbase, or at least a part of them. Maybe they just want to wait to see how the situation evolves...
I don't really know what their next move could or should be, I just threw in my two cents, but I would need to know more about how companies work to make a more consistent opinion...