I have the Ridgid BS1400 bandsaw from HD and that seems to be the correct assembly. In fact, mine arrived with the blade installed and that cover already in place as you described. The instructions for changing the blade include a step for removing the rear blade guard. While you may disagree with the design, it is not the fault of someone at the HD store putting it together wrong.
BTW, the brand name is Ridgid, not Rigid.
I knew that, just stayed with "Rigid" to follow the OP.
Seems like an unnecessary step. I'm going to go back & check my G0555, but seems it came with the open side out on the *back* blade guard. I know that's the way the directions said to install the new guard when adding the riser kit. The guard is deep enough to prevent accidentally touching the blade under normal circumstances, and if the blade was in danger of coming out of the guard, then there's *other* problems to worry about.
Not to mention, (and I said NOT to mention it), that the diameter of a belt-drive arbour is smaller and henceforth allows the blade to be elevated higher than a direct drive motor which will bump its little housing against the bottom of the tabletop far sooner.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.