Bobbi Althoff Reached Out to Oliver Tree's Camp Before Publishing Final Interview

Bobbi Althoff sat down with Oliver Tree for one of the late singer's final interviews, then published their conversation a couple weeks after his death ... but she didn't do so without a stamp of approval.

Sources with direct knowledge TMZ ... Bobbi reached out to Oliver's camp before publishing her interview with him on "The Really Good Podcast," and she got their blessing.

Oliver's appearance on Bobbi's podcast stands as one of his final on-camera interviews before he died in a helicopter crash in Brazil. It's unclear when they filmed the podcast, but Oliver died June 14 and Bobbi posted it 15 days later on June 29.

Their conversation has already struck an emotional chord with fans ... with Oliver reflecting on how unpredictable life can be. His comments turned out to be an eerie premonition.

At one point in the interview, Oliver told Bobbi, "We don't know if I'll be alive next year or you'll be alive. There's no day promised" ... before encouraging people not to take life for granted.

OIiver also talked about living a high-risk lifestyle, his creative process, and his personal life ... while still mixing in the offbeat humor fans had come to expect.

Bobbi says all revenue generated from the episode will go directly to Dr. Oliver Tree's Extremely Epic Grant for Baby Geniuses -- the foundation he established to support artists working in music, film, installation, and performance art.

The episode serves as both a farewell and a tribute ... giving fans one final glimpse of Oliver's unique personality while helping support a cause created in his honor.