I expect the loading screen was in large part to there being no smooth transition when sailing from one continent to another. WoW in its original form still ha

I expect the loading screen was in large part to there being no smooth transition when sailing from one continent to another. WoW in its original form still had "zones" where there was a small delay in moving between them. These delays were actually exploited by players for PvP purposes (ie camping those zone transition points).