He is born in Canada, but neither of his parents was Canadian so far as I know. It is possible that his father might already have applied for citizenship in Canada, but they arrived in 1969 and Ted was born in 1970. I suppose it’s possible for complete citizenship in a year, but I really don’t know. Perhaps it is impossible. I suspect there’s a residence requirement.
I doubt that by a technical definition he could be a natural born citizen of Canada. But he could be a citizen at birth by whatever law they have.
Bear in mind that Cruz renounced his Canadian citizenship in 2014, or was it 2013?