Can I deploy out of support versions like .Net Core 2.0,3.1 and 2.1 without upgrading in Azure App Service

Can I deploy "out of support" versions like .NET Core 2.0, 3.1 and 2.1 without upgrading to Azure App Service. I am trying to move my components from on Prem VM to Azure App service currently. I have tested this by deploying these older components to Azure app service by
creating web app using runtime stack: .NET 6 and Operating System windows
It looks like internally it picks the right runtime and executes successfully. For instance, .NET core 2.0 component runs on .NET core 2.0 runtime etc. Is there any issue with this? Can I keep this as it as until I upgrade to LTS version sometime soon ? Is it a mandate to upgrade to LTS version before deploying on Azure app service?
Thanks