Probably a case of "close enough." The Service Tech probably had nothing closer on hand.
When I usually come across capacitor "mods" like that, I'll check to see if it was prompted by a Service Bulletin. If not, I replace them with the same value (and type) that came from the factory, with a higher voltage rating, if possible.
I say "usually" because sometimes there are good reasons to go to a different type of cap. 60 years of progress cannot be ignored.
