All shelf variants are in the redstone section of the creative inventory

The creative inventory overhaul in 1.19.3 changed the redstone tab to only include different variants of the same type of block when they are functionally different. For example: Only one type of fence gate is included, but the bamboo raft with chest is included alongside the oak boat with chest due to its different seat position.

However, all 12 shelf variants were included in the redstone section, despite the only difference between them being aesthetic.

A case could be made for the lightning rod variants, but they at least represent different stages the block can go through, which can affect the behavior of a contraption.