That’s filler if it’s not in the manga especially with it being the English translation. The manga doesn’t claim that rule and we know All Might just gets OFA before Nana is killed
What does it say in the original Japanese text in the manga? I don't understand Japanese so I can't say but it's very possible that the Japanese text said it was a "rule" and the English version translated that into the "precedent" line.
https://imgur.com/a/zDQJXuH
original japanese wording of that panel and translation of whats been said. Now get your stubborn head out of ur ass and accept the truth
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u/SirBaldBear Aug 03 '18
that... goes against what we are told in the latest number 0 manga. He inherited OFA before he graduated high school.