DOOM Eternal has been delayed until March 20, 2020 in order to bring the game up to id Software's "standards of speed and polish." As an apology, id Software is including the upcoming DOOM 64 re-release as a pre-order bonus for DOOM Eternal at no extra cost. DOOM Eternal will also get a free DLC package shortly after launch that will let players enter another Doom Slayer's game as a playable demon.
https://www.notebookcheck.net/DOOM-Eternal-delayed-to-March-20-2020.437575.0.html