As of the current date, Bernard Arnault has not yet dethroned Elon Musk as the world's richest person. However, if such an event were to occur in the future, it would be a significant development in the world of business and finance.

Bernard Arnault is the CEO of LVMH, a luxury goods company that owns brands such as Louis Vuitton, Dior, and Fendi. Arnault has been steadily climbing the ranks of the world's wealthiest people over the past few years, thanks to the success of his company and his personal investments. As of the time of writing, Arnault is the third richest person in the world, with a net worth of around $182 billion USD.

Elon Musk, on the other hand, is the CEO of Tesla and SpaceX, two of the most innovative and successful companies in the world. Musk has been the world's richest person for brief periods in the past, but his net worth has been volatile due to fluctuations in the value of his companies' stocks. As of the time of writing, Musk is once again the world's richest person, with a net worth of around $190 billion USD.

If Bernard Arnault were to dethrone Elon Musk as the world's richest person, it would likely be due to a surge in the value of LVMH's stock or an increase in the value of Arnault's personal investments. However, it's important to note that the net worth of billionaires can fluctuate rapidly due to changes in the global economy, political instability, and other factors.

In conclusion, while Bernard Arnault has not yet dethroned Elon Musk as the world's richest person, it's possible that he could achieve this feat in the future. However, the wealth of billionaires can be unpredictable, and it's impossible to predict with certainty who will hold the title of the world's richest person at any given time.