I love Lemmy, but I feel like people are overestimating the ability of the platform. Stability and usability issues aside, there's the question of why would John Oliver come here? We don't have any history of celebrity AMAs, and highest estimates of our userbase puts us at maybe 1% of reddit, or 1 million users. For comparison's sake Ashens has 1.5 million subscribers on YouTube, do you think he could suddenly decide to do interviews and have the pull to get someone like John Oliver?
I think reaching out to Christian Selig or Louis Rossmann as other commenters suggested is more realistic, and would probably be a better experience for everyone involved.