Can confirm.
Just installed Orion RC and was surprised to see ads. Example:
macrumors.com

cbc.ca

This also occurs on a clean profile and there are no extensions installed.
Also, there are glitches with loading images sometimes that I can't reliably recreate but it happened to appear there. If I can reproduce I will file a new bug.
Orion
Version 0.99.123.3.5-rc (WebKit 616.1.4.5)
MacBook Air (macOS Ventura 13.4 beta build 22F5027f)