Hi,
You are of course correct that we should normally follow what upstream do; however occasionally we do change some defaults (for better or worse). In this case, I don't think it's clear, a lot of data (the Largo presentation, other distros, just observing users) might suggest the current default is not the best one. I don't know
This isn't the sort of thing we should diverge from upstream on. If it makes sense to change it for Fedora, we should lobby to get it changed upstream as well.
This case in particular is silly, since Alex (who wrote spatial mode) is upstream GNOME and downstream Fedora.
--Ray