VZ 52 ammo

Does anyone know why Czechoslovakia has been allowed to develop a totally different gun with a unique ammo calibre at the height of Cold War with SKS-45 and AK-47 in the field? And what happened later, they just switched to AK and abandoned VZ-52 production?

From: http://world.guns.ru/rifle/rfl14-e.htm

Strictly speaking, the 7.5x45 was an early prototype, the service round was the 7.62x45.

Not to forget the predecessor of the 7.5x45 which was a 7.62x45 with a different case shape.