Arianna Huffington lent her name and money to the website, but it is the content that has made Huffpo such a success. As long as their are competent editors who attract good writers, the website will continue to be successful. There is no reason to think that just because she leaves it will die.
Yes, the Huffington Post will continue to have success without Arianna Huffington. The Huffington Post will continue to be successful as long as it keeps its current format. If the new person comes in and wants to change the format, then it may begin to decline. They need to keep doing things the way she did them.
I think nobody is irreplaceable and Arianna has to focus on one venture than two in order to be the most productive she can be. Clearly, her new venture is not as political as Huffpost is. And clearly, it makes sense that she has to leave. The huffpost needs to hire a new hero than promote freedom of speech.
Arianna Huffington is absolutely amazing but I truly believe she will find someone very capable to take her place. There is so much talent out there that would be a perfect liberal fit for them, not to mention in this political season there's so much juicy stories so how can they go wrong. There's craziness at Fox News with the sexual harassment cases, Hillary Clinton's emails and the granddaddy of craziness...Donald Trump. It is all a newspapers dream.