Depends on what you mean.

I’d like to be at or near the first flight of a new plane using a time-tested design.

Failure rates (more specifically hazard rates) in most components tend to increase with time (I.e., follow a time-dependent failure model like a Weibull distribution and not a constant rate model). The “bathtub” curve is usually more associated with components with a constant failure rate (where the ideal place is after infant mortality but before wear out).

There are two types of uncertainties here and I think we’re talking about different ones. One is a design uncertainty that can be mitigated using a well-used and understood design. The other is a component failure uncertainty which increases as service life increases. So the ideal place to be is in a well-vetted design with new-ish components.

I not arguing about design uncertainty, rather production uncertainty. A failure in the production is more likely to fail on the first flight then the 3rd.

I don’t think reliability theory, particularly in aerospace, supports this claim unless the quality control is lacking. To be fair, SpaceX has had quality issues in the past but they seem to learn quickly from it.

To reiterate, the hazard rate tends to increase with service life. So as components age, there is an increased risk of failure.