Illidan, Maiev, and the others each returned to their own territories. Patrick and Kael'thas naturally had to return to Silvermoon City.
Kael'thas could not pledge his loyalty to Patrick, because he was still the nominal heir to Quel'Thalas, a descendant of the royal Sunstrider family. If he swore loyalty to Patrick, it would be tantamount to Quel'Thalas changing hands.
Thus, Quel'Thalas was now in a very delicate situation. Patrick was the Special Councilor of the New Silvermoon Council and exercised all the powers of a regent. But a regent was ultimately only a regent, inferior to a king in both status and authority, so Patrick naturally ranked below Kael'thas.
Yet with the existence of the Arcane Pact, Patrick was its acknowledged founder, as well as the shared leader of numerous factions and races. Even Illidan, famed for his defiance, had already placed himself at Patrick's command. What could the others say? What would they dare say? So long as their interests were not harmed, Patrick's orders were their objectives.
Looking at the members of the Arcane Pact as a whole, Vashj and Illidan were on the same side. Of Outland's three former great powers, only Vashj had been Illidan's true ally. The other factions, whether Kael'thas or Akama, had their own plans. Since even Illidan obeyed Patrick, Vashj naturally did the same.
Maiev had once been a priestess of Elune. Although she did not know the nature of Elune's relationship with Patrick, she knew that Patrick was Elune's spokesman, so she naturally obeyed him as well. As for Kul Tiras, it had long since been won over by the navy under Patrick's command, while Stromgarde, Aerie Peak, and the Syndicate all needed something from him.
Finally, the Animal Gods, Grizzlemaw, and the other factions that had joined did not ask