I don't know about the OP's instance, but an historically common reason not to state an intended use is so as to facilitate marketing of a device for a use that is not consistent with its classification, its premarket approval, or legal device boundaries.
FDA specifically addresses such circumstances. FDA will assume that any communication to potential users by (more or less) anyone that in any way encourages or supports a use is marketing and a declaration that that use is an intended use, and will regulate on that basis.
De facto marketing of products for uses outside of their proper intended use, if any, is (I think) historically the second most common reason for Warning Letters, after lack of proper complaint handling procedures.