1.5 years later: No fix was released.
The Microsoft Windows version of Doom was released on May 13, 2016, and a lot of users reported their save file was corrupt after a power outage, or if Windows or the game crashed their PC.
I can't believe id Software has yet to fix that issue that I experienced yesterday because of a power outage. All that they need to do is give you the option of reverting to the previous autosave, but that's apparently impossible to code in 2017.
The only clean solution is to manually backup your entire Doom profile which is listed below:
C:\Users\[your user name]\Saved Games\id Software\DOOM