raw broccoli or green beans are fine, most people don't feed broccoli to much tho it's pretty gassy even for gliders.
Frozen veg isn't raw. Vegetables are blanched prior to freezing... boiled for 3 minutes then shocked in ice water for 3 minutes. The blanching process kills bacteria and stops enzyme activity that can spoil food. Then they're flash frozen, which tends to preserve nutrients
If you were to freeze raw veg it wouldn't last as long as blanched veg does.
Frozen fruit on the other hand is usually frozen from the raw state and doesn't go through the blanching process.