Well, yes and no.
The very first versions of Cotton Candy and Blossom in Year 1 have flat hooves, as in the bottom of the hooves are entirely flat.
All the Blossoms and CCs sold in Year 2 have concave hooves.
However, some of the Blossoms and CCs sold in Year 1 ALSO have concave hooves. They were also offered as mail order ponies a couple times with concave hooves.
So basically:
Flat hooves - definitely from Year 1
Concave hooves - could be from the later part of Year 1, from Year 2, or from later as a mail order.
No matter which version you have, their hooves will be marked 1982.