Although the absence of a physical release resulted in many canceled pre-orders for GameStop customers, Nintendo Switch users will be able to get Doom Eternal as a digital-exclusive release. Sadly, there is only the official confirmation of this launch, but no accurate date to talk about yet.
https://www.notebookcheck.net/Doom-Eternal-headed-for-Nintendo-Switch-as-an-exclusive-digital-release-no-launch-date-yet.505379.0.html