FINALLY, Microsoft has pushed an update to the Report Authoring Extension for Dynamics 365 to allow for use of Visual Studio 2019. This update went live on 12/18/2020 and can be found here. Installing won't be straight forward into Visual Studio 2019, even if you install everything when you first installed it. This is because SSDT (SQL Server Data Tools) is installed but, SSAS, SSIS and SSRS are all separate modules for SSDT that you have to install separately. While you should be fine with just installing SSRS to make this work, I would recommend just installing all 3 parts.
All of these can be found in Microsoft documentation. In the "Install SSDT with Visual Studio 2019" section, you will see a link to the marketplace where you can download the extensions and install them. Once that is done, download the Report Authoring Extension and run the installer. That is it, you can now work on SSRS within Visual Studio 2019 for Microsoft Dynamics.