مَا مُحَمَّدٌ إِلَّا رَسُولٌ
Muhammad is a messenger and not beyond the human condition of messengership.
The statement corrects a particular expectation or misunderstanding. It is therefore reasonably discussed as relative restriction, not as an assertion that the Prophet has no attribute besides being a messenger.
Reversal restriction (qalb) addresses an opposing belief; ifrād corrects mistaken co-attribution. Subtype classification should follow the actual misunderstanding under discussion, rather than be imposed mechanically on a verse in isolation.