Yes; event layers present in an ArcMap document can be served over the Internet using ArcMap Server.
Note that an event layer is simply a feature layer based on a table storing either x/y or route locations. The process of calculating the shape of a route location so that it can be displayed on a map is known as 'dynamic segmentation'.
There are some limitations when displaying event data by way of ArcMap Server:
1. If the input event table does not have an ObjectID field, the layer cannot be viewed in a Java client.
2. If the input event table does not have an ObjectID field, any selection made from the layer will not render in an HTML client.
3. The features in an event layer cannot be buffered using an HTML client.