Not necessarily. CFRP is plenty strong to handle the task. But it's a complicated material - though not necessarily new. I think one complication people underestimate when comparing to steel or titanium is that CFRP is NOT isotropic - meaning that its physical properties are NOT the same regardless of orientation. Another is that CFRP has so many dimensions to its strength (e.g. orientation of resolved force vs fiver orientation, fiber diameter, fiber length, fiber material, epoxy material, etc). Yet another is the concept of fatigue life. Steel is very forgiving in this regard - as long as you don't strain it enough to reach plastic deformation, you're good almost forever. CFRP (and even aluminum) have a lifetime no matter what. In that case, you need decent non-destructive testing techniques of which I'm certainly not an expert.

I have one major unanswered question about it though...is there any reason they needed the weight savings one gets from CFRP? Every sub I've ever heard of requires additional ballast to dive even when using tried-and-true steel hull. If they didn't need the weight savings, it was completely absurd to use CFRP.