First of all, the Whole Food Plant Based diet is compatible with the vegan lifestyle.
A vegan eats a strict vegetarian diet. But it does not have to be a healthy diet. You can include soft drinks, Oreos, Ben & Jerry's non-dairy desserts, and potato chips in a vegan diet.
The Whole Food Plant Based Diet is a diet whose main objective is to promote a long life. It minimizes animal protein, oils, sugars, and processed food. So by definition, a WFPB diet is super healthy. Some people who eat a WFPB diet are very strict and use all the restrictions. Most of the authors of the WFPB diets allow for small amounts of all the things that are restricted. So a WFPB diet may not be vegan in that it might include small amounts of meat, eggs, and dairy.
I am a vegan but for the past couple of months, I have been incorporating more of the WFPB diet restrictions (according to Fuhrman). For me, the only big change (and the only challenging part) is the elimination of oil. Not cooking in oil, and not using oil-based salad dressing has been challenging. I've also stopped buying some of the worst vegan foods (For me its potato chips). I'm pretty much sticking to big salads for lunch and steamed veggies over rice for dinner. I've lost about an inch around the middle.