If I remember it correctly some of the Jem'Hadar appeared inthe novel Unity
. The Prophets sent a small number into some pocket reality or something and they threw the queen Conspiracy bug alien that was threatening Bajor into that dimension as well (or did Sisko do it?). Despite the time differences both appear in the reality at the same time. The fate of these Jem'Hadar isn't stated or what happened to the thousands of others.