Nigger I had the manuals open to confirm while writing.
I think it started with 3.5E and not 3E; not sure, I don't have the 3E manuals on hand anymore.
Here's part of p.33 of the 3.5E PHB, first page of the druid. Followed by p.42, the paladin. It's the same for the monk, rogue, wizard, and a lot of other stuff.
And here is the DMG 3.5E, p.11, with the switching between male and female pronouns when refering to a player. One could even say the connotations are more negative towards players with male pronouns, but I think that would be reading too much into it.
There is more obviously, those are just random pages I flipped to, manuals are like that all over.