"Stealth banning" or you could call it "stealth blocking" (also called shadow-banning or shadow-blocking) is a situation employed in a situation where one side sends a message and are unaware the message was invisible to the end user.
With stealth-ad-blocking, the website (server) will think the ad has been received but the user does not see it. Adblock, in between, sees it in its virtual browser context and doesn't display it to the end-user.
The server end has no idea that the user is using an adblocker and will not request for the adblocker to be disabled. (They don't see whitelist the site, they say disable the adblocker. Next they'll be telling me to uninstall my anti-virus software and firewall).