The Traditional Catholic Faith STILL keep August 15 as a Holy Day of Obligation.
Why because Our Lady said herself in the book of Luke that “for behold from henceforth all generations shall call me blessed.” Luke 1; 48
She also said that she increases your faith in her son. And Mary said: “My soul doth magnify the Lord.” Luke 1; 46
Therefore it is impossible to love her, Mary, more than Jesus, because the more you love Mary the more you will love her Son.
The spoken word was passed on to the original Christians the story of her Assumption into heaven, not by her own power but the power of God.
Assumption the word itself:
Word Origin & History
c.1300, “the reception, uncorrupted, of the Virgin Mary into Heaven,” also the Church festival (Aug. 15) commemorating this, Feast of the Assumption, from Old French assumpcion and directly from Latin assumptionem (nominative assumptio) “a taking, receiving,” noun of action from past participle stem of assumere (see assume). Meaning “minor premise of a syllogism” is late 14c. Meaning “appropriation of a right or possession” is mid-15c. Meaning “action of taking for oneself” is recorded from 1580s; that of “something taken for granted” is from 1620s.