Yes, as A1C Levels can be lowered...however some vegans are low in the B vitamins which provide energy.
In order to get my numbers down I ate no fruit for 3 months except berries...all kind of berries...raspberries, blueberries, blackberries, strawberries, etc., as they have the least impact on blood sugar.
Once stabilized I added low glycemic fruits apples, peaches, pears, plums, kiwi. I no longer eat grapes, mango, pineapple or bananas as they raised my glucose. I eat no dried fruit as it is concentrated sugar. I eat NO SUGAR FREE foods as that too raised my glucose.
I eat pasta only 2X a month and then a portion the size of a light bulb cooked and add green beans or broccoli to blunt the starch and sugar. I eat red meat only 2X per month for the iron and then it's filet mignon, sirloin, pork loin.
I eat a lot of seeds and nuts as they are beneficial in keeping my numbers steady. I monitor my protein as protein helps keep blood sugars steady. Also I drink lots of water and lots of fiber foods. Water and fiber are a diabetics best friends.
I don't think I could just eat veggies. My A1C is back to normal and has been for over 2 years.