It's something that was happening at least 20 years ago as well. Though specifically for pig farms' smell: regulations of how to deal with the smell has long existed and quite often if there's complaints they're not using the filtration system because it's expensive to maintain.

I live within 200m of a pig farm and I've never smelled it itself.

No, it existed long before covid. There is towns which made a contract for people moving there, which deny them the right to file against the church's bells noises or cow's moo by example.

In the article, which was a daunting 200 words, it talks about cases from 2016 and 2019.

Its been happening for a very long time. Usually its farms, but it applies to anything loud and/or smelly. Racetracks and gun ranges are good examples.