I think you mean If-Match and If-Unmodified-Since. Actually they are relevant for DELETE as well. E.g. you might not want to DELETE if another client has just PUT.
If-None-Match: * ensures that another client hasn't created the resource you are trying to create. It is equally important as If-Match for resolving race conditions.
It's fairly uncommon to use PUT for resource creation. In that case, however, if the server supported it, yes you could use If-None-Match. I really have to wonder about the architecture of the system, however, if two clients can simultaneously decide to create the same resource rather than two similar resources.
* Literally the first thing RFC 7231 says about PUT is "The PUT method requests that the state of the target resource be created or replaced […]". RFC 7231 takes into account many changes in HTTP practice over the past decade (even bizarre ones like POST-to-GET on a 301 redirect); if create-on-PUT were frowned upon, it would be called out.
* PUT as described in RFC 7231 is the same thing as UPSERT in an RDBMS, or a write operation in a key-value store. These are certainly not uncommon DB operations; their REST analogue is similarly useful.
Here's some examples:
* PUT is how documents are created in WebDAV. WebDAV is multi-user, so two users may decide to create a document with the same name, just like on any file system. If-None-Match: * is the only way to support the O_EXCL flag on POSIX open(2).
* A resource which represents attributes of arbitrary external resources will have a URI named after the external resource (e.g. UPC or SHA-1, etc.), and therefore must be created with PUT. If-None-Match: * is the only way to prevent lost updates when the external resource is first made known to the system.
PUT-as-create is sound design supported by precedent for any system where the keys have a priori meaning.
