I don't think that going back to Doom's original roots would be a good idea. It's old style of gameplay is a bit outdated. It's still playable cuz it is the foundation every fps out, but I don't think it is what people would want.
It also might me too late to reinvented Doom with the oversaturation of fps out nowadays and cod, it won't get overlooked cuz its doom, but it would quickly die or get unfavorable reviews cuz it prolly wouldn't bring anything new or do anything to separate it from cod. They should prolly wait till the fps genre dies a bit.
They also tried to give it a reboot with Doom 3 and it wasn't that well received by the critics and apparently some of you guys. But it was pretty good. I loved going around and collecting all the audio logs and other things and listening to them and getting kinda sucked in. And I liked playing the chicken punching game, lol.
I personally love the game and still play it ,both the originals and 3 and it's expansion, and would love another reboot but I don't know what else they could do to re-revamp the original barebones story or what they could do to make the gameplay standout. They would be borrowing a lot from other games and would prolly be like a call of duty version of doom, and that would be terrible. They should probably let it die. It ran it's course in the 90s and will be remembered as the game that started the fps's popularity.
I also think Dead Space took a lot from Doom 3 with the atmosphere and things you collect and the psx version of doom and doom 64 mainly with atmosphere and creepyness. So, in a sense, Dead Space is like the new Doom. That is until Isaac started talking.