It seems like the previous browser antitrust ruling in Europe was 2010, with the browser ballot screen being required until 2014.

Given the scale of the fine Microsoft received after breaking their agreement by breaking the ballot system and not showing it to users (over 500m EUR I believe), it seems strange to me that Microsoft is really so willing to get back into this area of making it harder to switch browser, given the ample past precedent.

Is user data gathered from the web browser under default settings really valuable enough to justify the risk?

Honestly, I don't expect antitrust to trigger here. With Apple's treatment of browsers on their phones being considered perfectly acceptable somehow (and the same can be said about pretty much every type of app store category, to be honest), I don't think there are any government bodies that even care about this type of antitrust anymore.

The fight for free access to app stores has replaced the fight for browser bundling.