OK, guy here speaking with a philosopher's hat. There's one quibble I have with a lot of recent neo-Buddhist terminology. That's the use of the term "metaphysics" or "metaphysical theory" as some kind of epithet, related to the claim that "the Buddha had no metaphysical view", or some such thing.
Here's the issue.
Firstly, maybe someone can correct me here, but I don't believe it's accurate to claim that in the Canon the Buddha ever claimed not to have metaphysical views. It's well known that the Buddha refused to answer several key questions regarding the eternality of the world, whether the Tathagata would exist or not exist after death, etc. However AFAIK he is not recorded as ever having said that he refused to answer these views because they were "metaphysical"; what he said is that answers to them were irrelevant to the attainment of enlightenment, which is a different claim.
Further, it's pretty clear from the texts that the Buddha did have relatively robust ideas about certain things that ordinarily would be called "metaphysical": e.g., the way dependent arising worked; how the mind worked; reincarnation and karma. (Exactly how robust his views were on reincarnation and karma is a matter of disagreement around here, I know, but I don't accept the view that the Buddha was a 21st century naturalist, much less a pre-incarnation of Richard Dawkins).
(Which, BTW, should make no difference to a committed secular Buddhist, since such a person should already be more than willing to deny that the Buddha was infallible).
Secondly, and more plainly, in philosophy the word "metaphysics" is generally taken to denote the objects and relations that one is committed to by one's theory. In that sense, every meaningful, consistent theory has its own metaphysics, the Buddha's no less than St. Thomas Aquinas's. Among the things the Buddha is committed to existing are such things as mental dispositions, feelings, dukkha, craving, hatred, meditative processes, the eightfold path, et cetera. That is his metaphysics.
Naturalism has its metaphysics as well: it is the metaphysics of science. As it is now, that includes such things as the objects and processes one finds in quantum mechanics; the various subatomic particles and fields. Being a bit more charitable, naturalism might include the objects held to exist in other sciences as well, such as chemical compounds, cells, and eyes. My point is not to provide a full picture here, but rather to say that all consistent, systematic theories have their metaphysics.
One may claim with some justification that (leaving aside issues about such things as reincarnation and karma) the Buddha's metaphysical system is relatively modest and compact, and requires no particular philosophical flights-of-fancy, the way so much theology seems to require. That's fine; I have no problem with such a view, and indeed tend to hold it myself.
But please, let's try to get away from the use of the term "metaphysics" as though it were something distasteful that must be got away from. That only confuses things, as it makes it seem as though the Buddha was doing something that he was not, and indeed that he could not have done insofar as he wanted to come up with a theory about how dukkha arose and how it could be extinguished.
As a footnote, I can envision a position saying that in the service of 'skillful means' one must be prepared to deny any given claim if it promotes clinging. This would be a methodological sort of anti-metaphysics, in the sense that it would counsel one to be prepared to reject any sort of view whatsoever, not only the 'wrong view' that the Buddha ordinarily opposed. I say I can envision this position, but although this might be one interpretation of Nagarjunian nihilism, I don't know that the Buddha anywhere actually claimed that this was a worthwhile methodology, and I have serious doubts about it, myself.
It is not typically seen to be right practice to deny, for example, that the path is a real and valid path, or that greed and hatred might exist in oneself, or that there is such a thing as wisdom. Insofar as one clings to those things, one must thereby in fact have wrong views about them; and then it is the wrong views that are the problem, not the things themselves. Further, it seems to me that if one were to engage in such a methodology, it would only be in the firm conviction that there were such things as greed and hatred, and that therefore to eliminate them one was pretending that there were not. If so, then the methodology would not itself have any bearing on the main issue.