Arguably: All European customers who bought a Fitbit are likely screwed anyways, Google has a poor history with supporting acquired product lines. While I am irritated about my data being acquired, personally, I'd also recommend against anyone buying a Fitbit while this acquisition is in flux, as Google might choose to terminate service to devices shortly post-acquisition anyways. And privacy loss is a harm as well.
In short, this acquisition is already harming everyone, and the EU is trying to prevent the most consumer harm.
We have no idea what Google's endgame for Fitbit is. Keep Fitbit OS or shove Android Wear on the brand? Focus on the Fitbit app or push everyone to Google Health.
Without knowing this, there's no safe bet in buying a Fitbit right now.
In short, this acquisition is already harming everyone, and the EU is trying to prevent the most consumer harm.