Since the Watchtower changed the baptism questions in 1985, a witnesse has to vow to work with the organisation, (i e follow their doctrines.) If you do not, clearly you are showing you know longer wish to be a witness.
The society have already shown that if witnesses do not follow the doctrines, then they are within their rights to say you are no longer a JW.
They may or may not make an announcement, but either way the witnesses know how they should treat someone who has rejected 'God's channel of communication.'