More context from the Fall Release and a link to the documentation:
Improve campaign conversions with Personalized Variant.A/B testinghelps you determine which version of your message produces the best results, but itโs rare that one version of a message is truly the best version for every customer. After all, while most customers prefer Version A, a few might actually prefer Version B.Personalized Variantis a new optimization feature for campaign A/B tests that considers these individual differences and automatically sends each customer the campaign variant with which theyโre most likely to engage.
