I contacted GHA in this matter.

A black member who falls down cannot earn local experiences in the new category, i.e. in platinum level.

A platinum member who becomes a black member - on the other hand - can earn another 14 local experiences (in the black category).

It makes no sense to me. And also, what keeps me loyal once I earned all my local experiences? It is a very, very nice program. But "something" is missing - points earning maybe? Or special promotions, e.g. sleep twice and get a free night?