Does my wife become irrevocably divorced – according to the Maliki, Shafi'i, and Abu Hanifa schools – based on my husband's oath that his friend did not contact him after traveling, and is there expiation?

The majority of scholars hold that if a husband makes his wife's divorce contingent upon a condition, the divorce occurs when that condition is met, regardless of whether the husband intended to effect a divorce or merely intended to threaten, emphasize, or prevent. Therefore, you have been divorced by your husband with one revocable divorce due to his breaking of his oath. If he has not divorced you more than once before, he may take you back before your waiting period expires.