my mom and sister says they can because they eat in the wild and nobody cooks it for them,
BUT i've read online that feeding any raw meats to a sugar glider can hurt their immune system, whether it be from the store or not.
it also said in the wild sugar gliders stay away from any body of water and are less likely to eat fish.
can they eat raw salmon? i read also a few glider people said not to feed them raw salmon and to at least cook it.

In the wild no one cooks for humans either, and yet most of us do not eat raw ;)

Gliders in the wild do not eat fish, and rarely eat meat (if we except parrots in tasmania, but that's already an anomaly, they've been introduced there and are not in their usual environment)

For fish, I would not give them raw, because fish have not been fished 10 minutes ago, they've been dead for hours, are thus full of histamine and bacterias.
Same remark would go for meat, it is not the same as eating it directly from an animal which has just been killed, it passed through a killing factory and is likely to have been contaminated by bacterias down the road (that is also the reason why it is not advised to eat raw meat for humans...)