They were always differentiated from Legendaries in the original language (Mew/etc. were called illusory pokémon to contrast the Legends and sub-legends).
>>54922666>it just took the translators a while to realize.No Satan, it took until TPC took the translations off NoA to fix it, because NoA were too invested in their own (incorrect, as it shakes out) term of "Event Legendaries" (ignoring Game Freak intended to distribute actual Legendaries going forward as events). All of the incorrect or dodgy translations in the early Gens were due to NoA localising with an agenda (telling Nob "don't use that correct word, use this incorrect term that retard amerikids will understand better"