I think it can work, but there are some potential problems that they'd have to consider when designing it. Interference with the sports stem can be avoided by giving attached bags a more vertical angle, and maybe making the block a little longer (but that increases the stress on the frame). Interference with brake/shift cables must be tested. Extra bending is one thing, another is rubbing from vibration, which can wear holes in the cables pretty quickly. And you have to make sure not to snag cables on the block when folding the stem, which could kink the cables. Finally the bags cannot be placed so low that they block the dynamo light, which sits next to the front spring.

A third party might not consider all aspects - for instance if it is designed with Pacific Birdys in mind, they may not consider dynamo lights, if those Birdys don't have that option (not sure). The Birdy designers must consider all of it.