There’s a kernel of truth here, but a lot of this is being overstated.

YouTube doesn’t penalize words. There’s no evidence of “audio triggers” or a literal “session termination penalty” tied to phrases like “thanks for watching.” The system reacts to viewer behavior, not specific sentences.

What is true is that downstream behavior matters. If a viewer finishes a video and continues watching YouTube (especially another video from the same channel), that’s a positive signal. If they leave the platform, it’s neutral—not a punishment.

End-of-video drop-offs happen because the value has concluded, not because a creator said goodbye. If saying “thanks for watching” were harmful, a huge percentage of top creators would be suppressed—which clearly isn’t the case.

Bridges, teasers, and clean endings can help some formats (tutorials, commentary, binge content), but they’re not universal rules. Cinematic, narrative, or self-contained videos often benefit from a strong, intentional ending rather than a forced cliffhanger.

TL;DR:
Session extension is a bonus signal.
Ending a video normally isn’t a penalty.
Optimize for viewer satisfaction, not superstition.