If the elites got a scare, they could go in two directions. Double down on the old regime and ruthless repression, or try to institute some reforms from above themselves. Some governments might be tempted to side with the liberals and nationalists to gain advantage in diplomatic and power struggles with other countries.
In this scenario, is Russia called on to provide troops to crush the revolutions? That also affects future developments considerably.
If they double down, there is no telling how long they could get away with it, but if there is another round of revolutions they will likely be communist!
The second scenario is more interesting, because it implies a back door to getting much the liberal program enacted anyway.