Hi, @Deole, Pushkar (Pushkar) Thanks for posting your question in the Microsoft Q&A forum.
Existing VNet-injected caches cannot be directly changed to use Private Endpoints. Instead, you'll need to create new Private Endpoint caches and move your workload to them. We have some guidance here that you can refer to.
Yes, the "momentary interruption where the client connections are reset" is necessary because of the failover between primary and replica nodes. For more info please refer here
I hope this information helps, please let me know if you have any additional questions.
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