Wow. SEC filings are required in order that the people who own the companies involved (these are public companies, so their owners can include just about anyone) have some idea what's happening inside the company they own. Without those regulations the market would be completely opaque and thus non-functional. If these bare basics are your concept of "heavy regulation" then you have no idea.
In more civilised places you can't just fire people on a whim like this. Capitalism is a very fast way to get somewhere, but without stringent controls both the journey and the place you get to may be very unpleasant.
It is no coincidence that the best big companies I've worked for treat their US employees more or less the _same_ as the EU arms of the same companies, even though US regulations don't require that. The EU isn't mandating anything unreasonable it's just prohibiting the worst excesses, so chances are if you (as an employer for this hypothetical) are doing stuff in the US that would be forbidden in the EU, it's because you're a jerk. (e.g. the US has no "transfer of undertakings" rules, but if you use the fact that you've bought a rival company as an opportunity to cut wages and benefits for all the acquired employees yes, you're a jerk).