It's definitely 'the way', but I'm surprised it's being presented as something brand new, not thought of before. Organics has supported this system for decades.
In a way it's what we do with our sheep pastures. We have let the native plants and flowers come back in their own time, by never ploughing and reseeding (for at least the past 20 years, except one bit we bought more recently which had been reseeded about 10 years ago). Our sheep love the varied vegetation and, as the article says, animals will pick what they want and need to eat.
When you stop using artificial fertilisers to get the grass growing in the spring, you reduce the incidence of problems such as grass staggers and scouring when the animals are exposed to very lush, soft grass too quickly. It means having to wait for the weather, but that's never been a problem for us, in spite of where we live.
We could probably cram a few more animals onto our acreage if we used fertilisers, but it hardly seems worth the extra expense.
The flowers and plants which appear also change over time, with increasing natural fertility. Some plants prefer a low fertility soil, so they die out - this includes clover apparently, as it makes its own nitrogen and doesn't like a highly nutritious soil. With our relatively low stocking rate with sheep only, we haven't noticed this effect yet.
For your buffalo, maybe you could introduce some of their favourite plants from 'home'?
PS - how could I forget - all those lovely flowers are wonderful for bees, of the bumble, solitary and honey varieties