It’s not only speculation, the whole argument is based on implications that this court ruling might in some cases contradict other court rulings and established law.

“… the ruling suggests much stronger responsibilities for social networking platforms, and the proactive monitoring and filtering of uploads is a difficult responsibility for most of the services that operate on the open procotols.”

So this means basically nothing for now until the legal aspect is sorted out and laws explicitly defining the responsibilities of social media platforms are harmonised with this ruling (or not…).