I don’t know if the statement is correct in this case but in general saying “we will never know” about a subject which we have incomplete knowledge isn’t a contradiction.

I can say, we will never know what the first human that got to North America had for lunch on their 20th birthday, and I think that’s as true as it could reasonably be. Sure maybe we’ll invent a time machine or some other technology in the future that invalidates it, but if you apply that logic then nothing can ever be stated as a fact.