MI_IS1 I can't speak to the support provided by all those various printers. Generally speaking IPP is well supported. It is how most iOS, Android and Linux devices print today. There are also free tools online to help check if your printer supports IPP. The standard supported by Microsoft , Mopria, does have a certification program and list of printers which are supported as well. https://mopria.org/ Please note that even non Mopria devices that support IPP will likely work with Windows since they implementations differ only a little as mentioned here https://openprinting.github.io/driverless/01-standards-and-their-pdls/
Regarding, PDF support, today Print to PDF is implemented using drivers and that will be changing with this work. The user experience will largely be the same but vendors will need to update their code. We are working to ensure the transition is not disruptive to users.