Yobit is an exchange, check it out on coinmarketmap or try googling yobit. I've noted that Yobit supports most of the forks.
And will we be able to exchange BTA in Yobit then?
Yes, you will be credited BTA once you hold BTC on Yobit.
That's correct, if you hold BTC on Yobit, you will get your BCA automatically from Yobit.