I’m talking about applications in general, not just MMOs. Lots of kinds of companies used to have these problems. I don’t know of a reason that this problem would be an entirely different beast in an MMO than in any other kind of application where many users are interacting in real time. E.g., an ecommerce app needs to know, in real time, whether somebody else has bought the last Looney Toons toothbrush, a stock trading system needs to exchange all kinds of data between millions of clients on the millisecond timescale. Most of those sorts of applications used to have this problem.
But definitely I may be missing something. I agree that as MMOs go, EvE has huge fights, but is there a reason that would be different than other kinds of applications that have huge numbers of users and real time info?