Logstash input google pubsub - clarification

I wanted clarification on the below statement in the docs for the logstash Google pubsub input plugin

All messages received from Pub/Sub will be converted to a logstash event and added to the processing pipeline queue. All Pub/Sub messages will be acknowledged and removed from the Pub/Sub topic (please see more about Pub/Sub concepts.

I would assume that the acknowledged messages will be removed from the subscription queue and not from the topic right?
cause that would mean that the message will not be available to other subscriptions.

can anyone clarify or confirm this?