Not sure what groups anywhere are exemplary transmitters of Buddhadharma. What do you consider a well-rounded approach to Buddhist teaching? Particularly since we're talking about Japanese Zen, which has a large stream of self-view as Ekayana based on recognition of one's nature and transcending divisions of the Three Vehicles.
In any case, mainstream Zen groups are certainly not unaware that the Mahayana has a large corpus of texts. What texts they use and how, along with what Zen-specific texts, will of course vary from one teaching line to another.
You can easily Google in the USA "Zen center ceremony", "Zen center sutras", "Zen center Buddhism", etc. and get long lists of places with activities focused on Mahayana texts, traditional ritual observances and so on. On the Soto side of things, the Soto Zen Buddhist Association (http://www.szba.org
) serves as the main organization and vehicle for communication with Soto-shu in Japan. On the Rinzai side there's no central organization, but Rinzai centers are few so it's easy enough to look them up. At our place in Chicago, the weekly study group right now is examining the Vimilakirti Sutra; we do this is in keeping with the traditional Rinzai understanding of the role of sutra study in one's overall training, and the time that one is to do it (cf. Shumon Mujintoron
, which is also one of our standard texts and among the required readings for folks wanting to take the 5 precepts).
The problem with these websites as sources, of course, is that they're designed as advertising for something that most non-Buddhists - the majority population in these parts - don't know anything about. So you get a lot of talk meant to stress welcome, accessibility and non-sectarianism. For example:
""Buddha" simply means "awakened one." His great teaching was that we can all awaken; that fundamentally, we are all buddhas— Jewish buddhas, Christian buddhas, Hindu buddhas, Islamic buddhas, Ashanti buddhas, Haudenasaunee buddhas, secular buddhas."
This kind of talk is pretty common. The intent is to stress that folks already adhering to some faith tradition are still welcome, and could still benefit. I don't know of any Buddhist site anywhere that says you must self-identify as a Buddhist and accept core Mahayana teachings or you're not welcome. Now, if you actually go to Daibosatsu, which is a monastery, you'll daily find yourself chanting sutras, bowing to images of Sakyamuni, Manjusri and Samantabhadra, observing ritual days like obon, doing extensive retreat training and so on.
In any case, from within the Zen view of itself I see no problem with saying that anyone, regardless of beliefs and self-identification, could experience awakening if they encounter a realized teacher.
"Still Mind Zendo emphasizes the practice of zazen (sitting meditation) above all else, recognizing it as a way for people to deepen their insight and realization of their essential self, which is nothing other than the realization of their lives. And because essential self, or essential nature, is not bound by the limitations of any religion or gender or path in life — not bound, in fact, by anything — we welcome people from all walks of life and from all religious or non-religious backgrounds to sit with us, practicing the development of a still mind as the necessary path to awakening.
Our singular commitment to zazen practice makes our sangha (community) a simple one. Apart from upholding the tradition of the basic Zen chants, we hold no services or other rituals, and we do not wear robes. We are, however, deeply committed to the teachings of the ancestors; to the discipline of the Way; to the attention to posture and detail; to the practice of being in the moment; and to the extension of that practice into every facet of our lives."
So this is a group with a lay emphasis that downplays the traditional ritual functions that would normally be done by priests. Which is fine if that suits their situation. Some more welcoming, ecumenical talk. If they want to say "essential nature", ok...I'd quibble, but there's certainly precedent for using words like that.
If you take issue with what you consider an over-emphasis on zazen: let's remember that these folks are not going to sit the 4+ hours/day, along with study, ritual and other practices, that full-timers do. They're likely normal folks who don't spend much time in daily life practicing and studying. So what's wrong with stressing zazen as the primary practice, and having occasional periods of intensive retreat as they do? I see they also chant basic sutras and try to remain present and aware in daily life. What's wrong with them benefiting in this way according to their capacity?
Again, boots on the ground is really the only way to know what the situation in a given group is, and what they're actually doing and studying. But in general, the trend I've observed in USA Zen groups at least is an increase in emphasis on Buddhist basics and Mahayana texts. Ritual and ceremony are more common...partly because a general acceptance of Buddhism is greater than in the past, and partly because westerners have inherited those ceremonial roles from retiring/deceased Japanese teachers. There is a greater emphasis on tradition for various reasons. Where you used to hear talk about "Zen", you now hear people emphasizing "Zen Buddhism". Even Sanbo Kyodan groups, which had such an impact on Zen here, seem these days to de-emphasize Sanbo Kyodan as an actual organization and self-defined reform movement, and instead stress that they incorporate both traditional Rinzai and Soto elements within their practice.
All of this is for the better or worse, depending on your orientation.