Hi, welcome to the forum from Louisiana. Glad you joined.
Not really. It sounds like you've already hatched some eggs and have chicks like that. Photos are always fun and might help, but even then it's more of an indication than a guarantee.
The assumption with a black hen is that she is black because of Extended Black. That's usually the case but not always. I've had chicks hatch with red down that grew black feathers because of the melanizers I mentioned. There can always be exceptions.
Assuming the hen is actually black because of the Extended Black gene, you'd think at least half her chicks would be black when they feather out, assuming she is split. Extended Black is very dominant. But that's only if there are not modifiers present that change the colors of black feathers. Like I said, exceptions.
Then there is the problem that just because a chick will eventually feather out solid black and there is nothing exotic going on doesn't mean it will have solid black down. If you follow this link you can scroll down and see photos of Black Australorp chicks. When they feather out they will be solid black but you can see the down has a lot of yellow in it.
http://www.feathersite.com/Poultry/CGA/Lorps/BRKLorps.html
If your rooster is white because of Dominant White then you should get a lot of white chicks, depending some on whether or not he is pure for Dominant White and Extended Black. All the stuff I mentioned above come into play so you can get exceptions.
If your rooster is white because of Recessive White anything could be hiding under that. Any colors, any patterns. And since Recessive White is a recessive gene it will have no effect on the chicks unless the hen also has it. Anything is possible.
Typically when you cross a white chicken with a black chicken you either get a lot of white chickens, a lot of black chickens, or some of each. I'd expect you to see a lot of black or white chickens when they feather out but it is very possible you will have some other colors/patterns show up even on the ones that are mostly black or white. Like I said, photos are always fun, even after they feather out.
I agree. Not knowing what colors and patterns you get when they hatch is tremendously exciting. With certain crosses of pure color/patterns you know what you should get and if the genetics are correct you will get that but when you start breeding crosses to crosses all of that is out of the window. It sounds like you may have crosses.