I need someone much smarter and more willing to engage on this issue to explain this remark or set it straight, pretty please and pretty-thank-you in advance
Think of the browser as an operating system, and a web page as an app. If that app is another browser, custom built, it could be built to prevent adblockers.
Inasmuch as any app, eg., a video player, can include DRM or otherwise lock things down.
This is feasible, but its unclear how successful it would be -- it would just start an arms race to hack it.