Unfortunately I'm afraid this will only be a very short term gain for society. In the longer term CEO-s will just muscle-up. They'll hire a whole bunch more security and bodyguards, armored vehicles, taller, concrete fences around their properties and show their faces even less in public. All on company expense, so from our, their consumers' money of course. They will become even more isolated, secluded and cut off from society, more paranoid and resentful about the rest of us, mere 'plebs'.
I'm not saying I don't understand why people are celebrating. But I don't think that this murder will help steer back society, inequality and corporate greed into a healthier, better direction. Instead it is just another step along the path to the dystopian future shown in so-so many sci-fi literature and movies. Where 99% of society has been delegated to a complete slave-like status, with ZERO financial security, self-determination, healthcare access and freedom while they spend day and night labouring endlessly, just to not starve or freeze to death. Which they still might, if they get in an accident or an illness which bankrupts them.
Meanwhile the 1% will reap ALL the benefits from the work of all the rest of us and they'll live like no king has ever lived before. Possibly their lifes extended to hundreds of years, flying around the planet between their mansions from party to party.
Murdering one or two CEO-s will not prevent this future I think. We will need a much, much wider show of rejection of this future if we want to stop it. We will need protests, demonstrations and show of unity. The rich will try to prevent this in every possible way. They will call the protesters terrorists, fundamentalists. Police will treat them as criminals and jail or even kill many of them. But if the society-wide rejection of this dystopian future is not shown in full force, it WILL HAPPEN.
When the state executes a convicted murderer, it is not terrorism. If someone murders their spouse out of jealousy, it's not terrorism. When a serial killer murders 10 people, it is still not usually terrorism.
But when a radical minority group wants to push their political/religious agenda and subdue, oppress the general population by randomly murdering a bunch of them - that IS terrorism.
All of the above are murders, but not all of them are terrorism.
The same is true for every other type of aggression, including doxing. They can be used for many things in many cases. They can be used as a means of oppression, or the oppressed can use them to fight back against oppression. Almost all forms of aggression can be used for the good of society (e.g. by the police against criminals, or by the revolutionists against their oppressors) and of course for bad reasons as well. It all depends on the situation.
So no, doxing does NOT equal terrorism. But it can be used as such.