Here's the changes between the last 13.x tag and the latest (at the moment) 14.x tag (14.0.2): https://github.com/standard/standard/compare/v13.1.0...v14.0...
Analyzing the changes I leave as an exercise to the reader.
Regardless of the effort etc. and whether or not these changes were primarily functional or related to marketing, I personally support FOS maintainers doing whatever they want with the software they offer for free. It would be trivial to make a fork of Standard without the adware if you wanted, and the MIT license explicitly allows it. So more power to feross for his free offerings! And complainers: put your fork where your mouth is.