Those "adblock test" sites misinform people, they should never be used as they lead people to make bad decisions regarding their choice of content blockers.[1]
Good read: adblock test sites can be wildly inaccurate (alerting to connections that never made it, given redirect to the local shim resource) and can easily be gamed.
[1] https://bugzilla.mozilla.org/show_bug.cgi?id=1985170#c3