I'm pretty sure I was a Bing insider, too. but now I get this, been like this for the past few weeks.
I also experience some new features time to time on different devices or with different VPNs (IPs). like I once had the ability for a short period of time to set "themes" for Bing, like Minecraft theme. it was a small background behind the "Microsoft Bing" logo at the top left.
I had other short-term features too, such as seeing a "Secure" tag next to all HTTPS websites in Bing search results. i really liked it but it's gone now.