This is mis-reported. This isn't a general ruling on whether scraping sites in violation of the explicit instructions of the site owners is allowed.

The judge granted an injunction prior to the trial proper, permitting HiQ to continue scraping LinkedIn in the lead up to the trial. He did this because HiQ credibly argued that if it couldn't scrape LinkedIn it would go out of business before the court had even determined whether what it was doing was legal. These sorts of injunctions are a procedural matter and quite normal.

https://en.wikipedia.org/wiki/Preliminary_injunction has more.