There is disagreement among BP-keepers & breeders on this, & I suspect more for the sake of their own convenience, some feel that snakes kept in racks can get along
fine without actual hides...as you said, feeling that the drawers function as a hide. I don't buy that, but it's your call. In my experience nearly all snakes like to feel safe
inside a hide that offers "back pressure"...the snug feeling that nothing can sneak up on them in a hide where the ceiling isn't too tall & the doorway isn't too wide open.
BPs are especially shy snakes that do not actively hunt food, but wait to ambush prey that happens by their hiding place. In addition, knowing that snakes will choose a
sense of security over the right temperatures (for digestion) ANY day, I'd recommend 2 hides for most snakes, one warm & one on the cool side of whatever enclosure.
This is what I do, but you'll have to decide for yourself what's right. If you find that your snake doesn't eat well without hides, you might keep this in mind. Snakes cannot
talk & tell us what they like...they either thrive or they don't, but I try to approximate the living conditions sought by the snakes I keep as IF they were wild & free to choose.