To answer your question, yes. Apple requires 80% test passage of all the tests on web-platforms-test in order to be considered as a valid browser for iOS so they specifically targeted this suite to reach that milestone
It's a pretty silly requirement because wpt is not really meant to be representative of all web platform standards. It includes tests for non-standard features and the majority of tests are simple unicode glyph rendering tests.
that was true until a few months ago due to a ruling in the EU. It's still currently the case that only WebKit can run on iOS but they're gearing up to change that
Their result is: 1974740 / 2152733 (91%)
They also have their own dashboards tracking this [2]
[1] https://wpt.fyi/results/?product=ladybird
[2] https://grafana.app.ladybird.org/public-dashboards/2365098a1...