I just realized the follow
The class SequenceSizeCompletionStrategy
appear in the API 1.0.x and in
Spring Integration Reference Manual 2.0.1.RELEASE
But no appear in Spring Integration 2.0.1.RELEASE APIAn annotation indicating that this method shall be used as the release strategy of an aggregator. If not present on any method, the aggregator will use the SequenceSizeCompletionStrategy.
See that the reference Manual and SI API are the same version 2.0.1.RELEASE