In a semantic sense, deregulation is the same thing as removing laws. De = remove, regulation = regulation. But what de-regulation really means is "the reduction or elimination of government power in a particular industry".

In this case, this law is basically an exemption. Putting the merits or validity of that exemption aside, if you remove the law, you're increasing the power the government has rather than reducing it. The courts now have the power over tech companies to enforce laws that make the tech companies responsible for what is posted on their platform.

You could easily imagine a flipped situation where people were trying to add regulation to get the same final effect.

I suspect most people think more holistically about regulation than that. Being afraid of being sued and the results of those of those cases being enforced by the government certainly could be interpreted as “bigger government”/more regulation.