And that's fine, as long as the bike is never ridden under frigid conditions.

Note that, again, (i) freewheels never come greased from the factory; (ii) if there's a downside to using light oil as intended by the manufacturers, I've never encountered it or heard of it; and (iii) for some reason, people who advocate greasing freewheels on the basis that every other bearing assembly on the bike uses grease never mention, e.g., Sturmey-Archer internal-gear hubs, whose manufacturer has always specified the use of oil for maintenance for over 100 years.

S-A hubs use heavier-weight oil, of course, since the forces involved are higher. All a freewheel has to to is freewheel, so lighter oil is appropriate, as demonstrated by the fact that that's what the manufacturers of freewheels have always used.