In my opinion , I’m sure it can be measured with instruments as being real. But, can those measured differences actually be heard or just our ears and brains adjusting to the new component/ speaker?
Here’s a good test: Buy a set of used speakers. If they have been used for several months, years or even decades, they can seem to change their sound over the first few days in your existing system, even though they are fully broken-in. That’s just you adjusting to how they sound.