More likely over time.
I recapped my Tek 475 (vintage 1973) some years ago. Supply ripple was so bad, it was modulating the vertical amplifiers, and causing bias shifts.
Did my TDS460 a few years ago. This is the version with the shitty SMT caps that leaked and corroded traces. The TDS460A supposedly is fine (but will still be prone to age and temperature related failures, as all electrolytics are).
A Tek 2430 is certainly of the age where you need to check quality of the caps. They might not need to be replaced, but they might not be fine, either.
Often, general system diagnostics will fail, signaling capacitor failure. (In the case of my TDS460, errors popped up on the Acq, CPU and interface boards -- basically everything. Scopes that don't have diagnostics, YMMV.) When this point comes, replace everything.
Tim