I kind of think that a lot of foods (Acai, flax, quinoa) get written up in one study (re; it takes lots of studies to show evidence that something does something) and then it hits magazines and then we are all buying it. And then it goes into pet food.
I bought some ground flax to put into baking because I was curious (whole flax is not processed by the body)-it's touted as a weight loss thing but also for having omegas. So anyways here it is
in 3 tbsp you get only 6 grams of omega, and only 8 grams of fibre. You do get 150 calories, 10 grams of fat -and 1 gram of saturated fat. TBH it doesn't actually sound very healthy or very high in anything desirable. I think it's a 'trendy' food.
Now with all of that, we have a few studies that show it's somewhat good for people and likely none that show it's good for dogs, and likely fewer that show it's good for bunnies.
There are so few nutritional studies done for animals.
I'd go the safe route-if it's definitely safe to give, and may have benefits, try in moderation. However knowing that seeds just aren't good for bunnies, I just wouldn't
But check with your vet definitely!