Yeah I’d say it’s definitely real, most take around the 70 hour mark to fully break in, but some need a bit more.
I’ve heard speakers fresh out of the box and then a few weeks later. I’ve also heard speakers that are broken in compared to the exact same speakers fresh out the box, and you can generally hear an instant difference, mainly to the lower end.
I worked in home cinema and hifi for over a decade, so have heard lots and lots of speakers in that time, that’s why I’ve managed to do direct comparisons.
There’s no need to pay someone to do it though, just wire them in and play stuff through them, give it a month or so and enjoy.
Staff discount.