If Illidan was caught before reaching the Eastern Kingdoms?

A big What If, I know. But after rewatching some dialogue cutscenes from WC3/FTF, I realized how expansive this could be.

• Kil’Jedans agent is now off the board to destroy the Lich King.
• The Lich King was never attacked. Urgency on Arthas going North should be greatly lessened.
• Arthas has no call/urgency for Northrend and intends to rule his kingdom with Kelthuzad and Sylvanas. No undead break their bond.
• Kael’Thas never meet up with Naga.
• Garithos is a prick.

I’m guessing the entire Plaguelands become a plague/death-ridden version of Ice Crown? I don’t imagine the Death Lords finding much success here, Arthas should be able to steamroll anything. Maybe he takes out the Amani and Wildhammer.