Steps to reproduce:

1. Using the template available at: : https://www.zabbix.com/integrations/rabbitmq ;
2. Add it for monitoring in a Query in your RabbitMQ that returns more than 64KB of Information ;

Result:

Results in the impossibility of monitoring due to the limit of "Text item value is limited to 64KB", as informed in: 
https://www.zabbix.com/documentation/current/manual/config/items/item#text_data_limits

Expected:

From what I looked for in the official documentation, this limit has not been changed.

So, I suggest changing the Template as below:

Adding o Query fields in RabbitMQ: Get queues item:

columns

name,node,vhost,memory,messages_ready,consumers,messages,message_stats,messages_ready_details,messages_unacknowledged,messages_unacknowledged_details

In this way, we avoid breaking the monitoring due to the 64KB size limit of the Text Item.