That’s an excellent question. At the moment, the answer is no. Anything uploaded to openkim.org is visible to the public. The issue of “private models” has come up before, mostly in the context of proprietary models developed in industry. We have to see whether this can fit into the open source approach adopted by OpenKIM. There are also concerns of liability associated with keeping private models secure on our resources.
You raise an interesting variation on this problem that we have not considered before, i.e. a situation where it is desirable to keep a model private for a limited duration for some reason. It may be possible to come up with a technical solution for that case. We will consider this further and would be happy to discuss this with you and other interested users.