In the interview above Todd Howard states that Elder Scrolls VI is in pre-production and that they will be doing Fallout 5 after that. He calls their slate pretty full going forward but also states that they have other projects that they look at from time to time. He admits the games take a long time to develop even though he wishes they came out faster. However he wants the game to be as good as possible before they release.
Fallout 5 is in the pipe. Let's hope it never comes out.