I think this is possible to be achieved through group policy editor.
https://social.technet.microsoft.com/forums/windows/en-US/c20c4c47-092d-4daa-b4a8-154b3852e13d/using-group-policy-to-set-windows-font-dpi-size
This is the link to change font size in accessibility for all user with group policy
https://markswinkels.nl/how-to-push-default-font-in-outlook-2010-using-group-policy-preferences/
Link to change font for outlook with group policy.
https://www.geek-computer.com/wiki/how-to-change-the-default-system-font-on-windows-10
Registries related to system default fonts