If ontology is the science of being, we have Heidegger, who in the opening to Being and Time wrote:
Within the framework of the following fundamental elaboration of the question of being we cannot offer a detailed temporal interpretation of the foundations of ancient ontology - especially of scientifically highest and purest stage, that is, in Aristotle.
And
Being is not a genus of beings
But QM is about a genus of beings: elementary particles in their most elemental mode; in this sense it is not about Being in Heideggerian sense, in the sense he uses it in Being and Time; but it might be in sense of being, that Aristotle uses when he is being scientific in the sense we would recognise today, were he our contemporary - he is already a contemporary for Heidegger.
To this end, it might be worth quoting Rovelli on QM:
in spite of 70 years of development ... QM still maintains a remarkable level of obscurity; ... it is difficult to overcome the sense of unease that QM communicates. The troubling aspect of the theory assumes different aspects within different interpretations ...[notwithstanding that] some of these objections may be naive or ill-posed.
Rovelli suggests a comparison with the discovery of SR, where the formalism was more or less discovered (by Lorentz) but the actual physical principle that lay behind the formalism had to await Einsteins contribution - that simultaneity was not absolute, but relative, and which implied the revision of the Newtonian conception of space and time.
According to Rovelli, we again have a formalism but not a properly physical principles for QM.
Many interpretations have been investigated, but none have really achieved the level of consensus that SR did.
It's probably worth emphasising, given that this site is philosophical, that ontology isn't purely orientated to the thing-like things that physics is concerned with - for which the qualifier physical might come in useful, as in physical ontology; for example, one could compare that sense of ontology with what I began with - Heideggerian ontology - which is more concerned with:
The being of this being as it is related to its being
Which has a family resemblence with the Socratic injunction:
gnothi seauton (know thyself)