Please kill Wikipedia so the human race doesn't get any dumber because of it.
Lets put this to bed right now. The charging anode must reach a particular set of conditions to cause oxidation. Temp, current and charge level have to be above certain limits. First and foremost, you have to get the charge above 4.2V. Go read the voltage on a phone when it hits 100% charge they read between 4.0V and 4.1V.
Now why do they do this you ask? Because they know people are going to leave the phones on the charger overnight and they don't want to deal with warranty claims.
So lets Cliff Note this one:
Three things have to come into play to cause oxidation on the anode.
Cell phones quit charging below the 4.2V threshold.
Phone makers don't want to lose money.