But that's not how English works. When you pull some words out of a sentence and exclude others, you often get another sentence with a different or nonsensical meaning.

It's "company must [ (1. voluntarily recognize union) or (2. hold election) ]". Choosing option 1 is voluntary because option 2, which you elided completely, exists and may be chosen instead. The "must", on the other hand, denotes the overarching mandate to select from the enumerated options.

The part that the ruling the article is about changes is after that, BTW. The penalty for interfering with (2. hold election) is no longer a redo of the election, but rather imposed recognition of the union and a mandate to bargain with it. The previous penalty wasn't much of one and thus provided no deterrent for companies.

They're not required to voluntarily recognize a union though, are they?

Companies have the option to allow workers to hold an election to recognize or reject a union.

Right. It's more that a company already had the option to voluntarily recognize the union. This says, if they aren't willing to take that option of voluntarily recognizing it, they must do something else (hold an election).

> It's not merely semantics to point out: if a someone must do something, then it's not voluntary anymore.

If you have the choice between:

* letting the union election go on unmolested, or

* recognizing the union without an election.

The latter would be voluntarily recognizing the union (instead of exercising your option to demand an election).