Is this considered Formative or Summative Usability Study?

An A/B test done to introduce two new designs, version A and version B, collects three metrics, number of steps to reach page, System Usability Scale (SUS), and one question which uses Likert Scale.

Based on the above details (I made them up), can this be considered a Formative or Summative study?

I have been Googling around and reading in different pages, and PDF books, but there is no clear definition regarding this.

This website, https://www.nngroup.com/articles/formative-vs-summative-evaluations/ by Nielsen Norman Group, gives the following:

Formative: evaluations focus on determining which aspects of the design work well or not, and why. These evaluations occur throughout a redesign and provide information to incrementally improve the interface.

Summative: evaluations describe how well a design performs, often compared to a benchmark such as a prior version of the design or a competitor. Unlike formative evaluations, whose goals is to inform the design process, summative evaluations involve getting the big picture and assessing the overall experience of a finished product.

But, for this made up thing, the users get two test two different designs, i.e. specific selected users, prior to deciding if A or B shall be picked based on their final statistics.

Also read, Formative vs. summative research Quick and dirty versus slow and rigorous usability research.