Actually yeah it will....Here's the scenario:
Guy removes lower unit, replaces water pump or whatever... and reinstalls the lower unit, Shifting is off so he compensates by adjusting the shift cable barrels, gets it to shift (static) and calls it "a job well done".
I see it all the time.
There are other LIKELY possibilitys such as the bearing carrier either has been removed and not re-seated properly (allowing the propshaft to have too much end play), or the carrier retainer is broken and the carrier (and p. shaft) has slid back.
OR there could be a broken cam in the control box assembly.
OR it could be that the owner has crappy shifting practices and after several years of it he has damaged both fwd. AND rev. gear cogs simultaneously.
Or something has broken inside the gearcase and a chunk of it is floating around in there.
Thick cold lube can exaggerate a problem, but it's not gonna create one that doesn't already exist.
Make sense?