A decision must be made to determine whether to replace gutter fascia. I am replacing a faulty / questionable soffit install:

I am at a decision-point: if the fascia is to be replaced, now is the time to do so before any more soffit work.

The photos below show replacing the soffits with radial pieces. It also shows removal of the old gutter sections. Gutters were removed exposing the aluminum facia:

The remaining gutter in the left of the photo was installed 12 months ago and will be retained.

QUESTIONS

There are a few small nail holes that could be filled in with sealant. If there is no damage to the wood under the fascia:

What are the reasons to replace the exposed aluminum fascia?
How do I test said reason to determine if replacement of the section is necessary?

I intend to add gutters soon, however, I need to understand why I would want to replace the existing fascia, so I can develop a "litmus" test to decide whether or not to replace.