Gypsy Rose Blanchard is letting the world know that she believes Ken Urker didn't commit suicide ... and she's standing ten toes down on that.

Gypsy Rose updated the anti-cyberbully petition she launched in the wake of Ken's death ... mentioning that "we do know with 100% certainly that it was not suicide."

She says the official cause of death is still awaiting toxicology results, but she's confident her partner didn't kill himself.

But it doesn't seem like she's implying anything nefarious -- she goes on to say that the cyberbullying Ken experienced caused him to develop "unhealthy coping strategies" through drugs and alcohol.

Through her petition, Gypsy Rose is trying to create Kenan's Law -- Ken's legal name was Kenan -- to implement "pattern-based harassment reporting" when it comes to cyberbullying, as opposed to approaching every instance as an isolated event.

She's also pushing for human reviews of serious and repeated cases, report and evidence preservation and transparency and accountability from social media platforms.

If you or someone you know is struggling or in crisis, help is available. Call or text 988 or chat 988lifeline.org.