Using the following parameters
var params = { prop: 'revisions', revids: revId, rvprop: 'ids|timestamp|comment|size|flags|sizediff|user', rvdiffto: 'prev' };
I can obtain a diff of the revision revId compared with the previous revision. I can get the revision id of the previous revision via this query but there is no way to know what the next query is.
I would like to also have the next revId so I can render a link to the next diff in the series without having to perform a second HTTP request as I do not need the next diff.