As someone with 20 years of professional experience in the game industry, I find it interesting that you compared this jam to an "interview test". I've been fighting to kill interview tests in our industry because they hurt more than they help.
My favorite example of this was a struggling mid-sized studio that was in desperate need of a solid coder. They ignored all the evidence that these tests are bad practice and refused to change their ways. They ended up turning down a coder with the exact experience they required just because he isn't good at tests. That game studio no longer exists. The coder was quickly snapped up by Blizzard and is now a high-paid dev with credits on some of the industry's biggest tiles.
Also, in my experience, most of the devs will probably not take into consideration how long someone has worked on something or what their experience level is. Since most professionals specialize in a single area, their personal background may prevent them from taking those things into consideration. (It's unusual for an art director to know how long it takes to code a complex feature, just as few coders know how much time it takes to animate a difficult walk cycle.) I've seen devs tear down student projects with a team of 2 the exact same way they would a professional demo with a team of 20. In fact, if they really are looking for potential employees, they will probably be harsher than normal.
Most studios care more about dedication than raw talent because so much of game development is a boring slog of bug fixing and minor adjustments. Letting people continue working on their projects demonstrates dedication better than a one-off jam competition. I know if I were hiring right now, I would be more impressed by someone who has gone out of their way to incorporate user feedback and improve their project than someone who just gave up and moved on to the next shiny new project.
TL;DR - I support the idea of either unlocking people's submission pages or permitting everyone a one-time update prior to bringing in the pros. Just my two cents as an industry professional.