First it is tarot, not taro. Minor difference but important for clarity in some people.
Second if you don’t know what the deck of many things is I pity you. You have clearly never been engrossed in a game of D&D.
Thirdly use of a tarot deck as a prop for the Deck of Many Things is allowed by the reading of the game, as is a deck of regular playing cards. The deck is responsible for the complete chaos of many a game; some to detriment; some to greatness
It would be insufficient for tarot (78 cards) but perfect for oracle (as per the video), a similar form of divination that i have no direct experience using
Well, there are 65 cards in the box. A lot of the cards are the same as tarot but it doesn’t have the base cards of the minor Arcana ie: wands, cups, pentacles, staves.