The weakest link in any electronics is ALWAYS the electrolytic capacitors (also maybe mechanical relays too, but for this specific conversation, they do not quite matter). One of the most important factors in their reliability is the temperature and the voltage they are exposed to.
In theory, since class A amplifiers run hotter, all else being equal, it is possible that such capacitors may degrade and eventually break down, sooner than they would compared to other class of amplifiers.
However, if the capacitors are chosen to be of a very hi quality (very long lifetimes & very high temperature & voltage capability), AND they are appropriately placed in the amplifier enclosure where they are not always exposed to high temperatures, they could in theory, last quite a long time.
So, a blanket statement cannot be made but it is something which depends on a lot of factors.
Take this capacitor for example, it is extremely well made, have a very long life and they can withstand high temperatures (37,000 hours at 105C).
https://www.digikey.com/en/products/detail/kemet/PEG130MH3900QL1/4918903
If similar good components are used throughout, your amplifier will indeed last a long time too.