Why does a subscription keep fetching documents when oplog is disabled?

I have a subscription with disabled oplog (Meteor version 1.6-rc.13).

Meteor.publish('subscription, function() {
  const someQuery = {};
  const options = {
    limit: 10,
    disableOplog: true,
    pollingIntervalMs: 60000 // 1min
  return Collection.find(someQuery, options);

I would suggest that the subscription fetches 10 documents every minute.
But Kadira tells me something else. The screenshot shows a similar publication where I suggested like 100 fetched documents per minute due to number of active subs.

It looks like the observer is still reacting on changes to the Collection. The collection is updated very frequently, so I can not use Oplog here (bulk updates).

Is this a Meteor 1.6 problem or normal behaivor?