Not something I would recommend. You still need a writable Domain Controller for the Exchange Server to use in Azure, you can't use ADDS.
https://learn.microsoft.com/en-us/Exchange/plan-and-deploy/deploy-new-installations/create-azure-test-environments?redirectedfrom=MSDN&view=exchserver-2019
Seems like a lot of work and resources for little value.
I would keep it on-prem.
Also. Exch 2013 should be at CU23. Is that what you meant? When you run the Hybrid Wizard, it doesnt affect the existing server but make sure you read all all about it and understand how it works and the requirements
https://learn.microsoft.com/en-us/exchange/hybrid-deployment-prerequisites