But why it's not a 6.2 version? It would�� be more clear since this is continuation of version 6 with new changes. How one would revert to original 6.1 if this new version isn't working for him?

In the same way as any previous image version... e.g.

Pharo 6 is actually Pharo 60508 and lower,

Pharo 6.1 is Pharo 60509-60539,

and Pharo 6.2 is Pharo 60540+

(give or take couple of versions, don't remember the precise boundaries)

and you can download any specific image version you want https://files.pharo.org/image/60/

(it is a bit confusing, but Pharo 6 is not yet using git and the existing infrastructure is not keen on minor releases)

Peter