Second generation born abroad will be effected by this. An immigrant to Canada, who becomes a citizen has full rights as a citizen born in Canada. Their children born abroad are automatically citizens. That hasn't changed. A Dominican born immigrant to Canada can apply for citizenship become a Canadian and return to the DR to have children with their Dominican spouse. These children born to a citizen are Canadians (1st generation born abroad). It's the grandchildren who are affected.
Now let's say I lived in the DR and adopted a Dominican child, that child would automatically be a Canadian citizen after meeting all the adoption laws of both countries of course.

If that Dominican born adopted child (1st generation born outside of Canada) had a child in the DR, this child (second generation) would not be a Canadian citizen. However the 1st generation born abroad could sponsor them and once they arrive in Canada, they would be able to apply for citizenship immediately.
I think the second generation born abroad has until April to apply for their proof of citizenship before the new law comes into effect. I actually know someone who is in this situation. I let him know about it a couple weeks ago, I don't know if his daughter will act on it on behalf of her child. By the way, there are plenty of Canadian grandchildren of British subjects that are taking advantage of their ancestry to go and live and work in the UK. My daughter lucked out on that... she gets to be Iranian.
I just saw Lambada's post now. Yes that's correct.