I am not Muslim, but my mother and brother are so I grew up in and around Islam. I think the problem with going the route of declaring specific types of software haram would be that whatever criteria you'd set to draw that line would likely eventually get you to a position where using computers is haram; it's not like there are ethically-sourced microchips, or FOSS replacements for Intel Management Engine (IME) and closed-source firmware, for instance.
There is actually a now-defunct version of Ubuntu called Sabily that my brother used to use, that focused on providing 'halal' apps for things like azan notifications.
So I think it's fine and even good to try at only using FOSS tools as much as possible, but I don't think it would make sense (or be workable as a strict doctrine) to proscribe non-FOSS software.