I found WoW to be more social than EQ, but that was partially because we had a group of 6 or so EQ players, most of which were from the top EQ raiding guild on BB, rolling through the game. I don't think I soloed in Vanilla/BC/WOTLK WoW more than 10% of the time on my main.
From what I remember, the last 6 months of EQ before WoW release saw full adoption of voice coms too, which made chatting during every single activity so easy. There was no way EQ text chat could hope to match the social aspect of that.
Once getting max level, we joined a bleeding edge raiding guild and 40+ people on voice chat far surpassed anything I ever saw in EQ. Even outside of voice chat, there were a whole slew of people sitting around text chatting in the main cities waiting on PvP or for friends to log on to get groups going. Hell, we even ended up playing a bunch of DOTA games with some people from our bitter rival bleeding edge guild, who tried to grief us on green dragon and world boss kills.
Southshore VS Tarren Mill alone was more social, in global text chat, than anything I remember from EQ and half the people in the zone couldn't even talk to the other half.
That said, I'm not delusional enough to think that that moment in time can ever be recaptured. Same with EQ.