FillyofDelphi
Banned
Well, intervening on the side of the Serbs does seem like it would drive a wedge between the Austrians and the Russians, possibly killing the League of the Three Emperors early. What would Germany have to say about this, however? IOTL, they obviously retained their Austrian alliance, and if that same course of action was followed here, that would also put them on the same side as the Turks. I'm guessing this would result in multilateral arbitration rather than an escalating war, since that's how these things usually ended up at this time.
In Britain, Salisbury has replaced Gladstone as PM by this time, and while he wasn't as Turkophobic as Gladstone, he still didn't favor them quite as much as Disraeli had. Might not take too kindly to their act of aggression, but would also want to balance their interests against the Russians. A lot might depend on what the situation on the ground is by the time everyone agrees to stop fighting.
Act of agression? Bulgaria is currently trying to take control of East Rumelia; a province under Ottoman control due to the Great Powers deciding it should be so at Berlin and that the situation in the Balkans ought not be changed without broad international consent. Any Ottoman action could be easily spun as defensive and, in the Powers want to keep dangerious preceidents out of international law in how to deal with substates/autonimous regions unilaterally expanding their bounderies would likely do so if the Turks both protest and back it up with effective action.