I think it depends on the nature of the change. There are some changes that cause the subscription to be dropped, and thus the client queue to be destroyed (queued messages included). I’m not sure if the docs cover the specifics. I recall that IS sometimes warns about the queue being destroyed but I’m not entirely sure about that.
You’re right to be cautious, if you don’t want to lose messages. If you can’t find the info in the IS or Broker docs it might be worth a call to wM tech support.
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