In Germany the current government had the idea (but never follow through on it) to allow a married couple to form a new last name based on their last names. Funnily enough the article mentions that this meshing of names is already possible and getting more popular in the USA and Great Britain.

https://www.rnd.de/panorama/namensrechts-reform-kann-man-bald-zwei-nachnamen-vermischen-3AOXUKZP6VFV3IFKWBFLKWXBQY.html

Do you have a link?