anonymous user I have reached out to my team and got the update that it was something the product team has started to roll out as an experiment, but as there were major issues that stopped them from rolling it out more widely.
Unfortunately, as there are some potential incompatibilities with rolling back to the old designer style for the users where the user have already in the trial for this therefor the product team has given them the option with the button to them to roll them back if they chose to.