[morzh]

Recap usually does not trigger recalibration if only because those caps you change are not those affecting the oscillation frequency at all.
Sort of like when you recap your radio the caps that are affecting the frequencies, the mica and pods, stay put.

The age does trigger recalibration as parts develop deviation, which is within specs, but will affect the frequencies.
However, if it is a round dial thing and is not a digital display thing, the dial is for reference only and can never be treated as a precise setting tool, so again the recal is not necessary. A digital synthesizer-type generator on the other hand should be calibrated as typically the set figure on the display is treated as a precise reference.