Yes, with the additional possibility that the game might also succeed if the positive space happens to already be ideal for the emulation of that concept, that's just difficult because frequently a concept and set of activities that concept engages in will be nuanced enough to be hard to target in the context of different players-- but like if your character touchstone is Peter Parker hanging out with other troubled heroes, then yeah maybe the Janus playbook in Masks is exactly what the doctor ordered, and even when you're playing to find out what happens, what happens never leaves the comfort zone, but it requires you to be pretty much exactly in tune with the expected vibe. But that has to do with how the player interprets the desired fiction, if they want the actual drama of comic book peter's secret identity that works great, but if it's more about the fantasy of a webslinging hero running around kicking face and just solving crimes, the secret identity social stuff is potentially impositional so an OC game would let you choose via the deployment of that negative space, or just not include it.
But part of what we're grappling with as well in this thread, is a separate distinction: Where does the inspiration for an OC, their concept, and their requirements come from? That question is clearly mutually inclusive of different answers, there's the example of a player emulating characters from movies and tv and video games in whatever system even if its a tough fit (this comes up a lot with characters that don't do progression in games about progression), there's people who are reading through TTRPG manuals and getting inspired so they're on the right page, there's people inspired by the meta in a game where a combo that is extremely crunchy essentially sells its own flavor as a new or otherwise unintentional trope (ever see someone get super attached to an implementation of a build in a particular game and not be able to let that go?), there's people who kind of get a vibe from something TTRPG but didn't read it super closely either so what they imagined is not quite on point, or even people who say "I always play this sort of thing, what's the closest I can get to X in these other games."
There are a lot of different answers even for a single person, and they influence what I think we could consider the prelusory-to-lusory pipeline in your terminology. Then there may or may not be flexibility, I've taken an OC up through her third entirely different implementation-- she started as a 4e enchanter build, then eventually became an Order of Whispers Bard in 5e because I wasn't happy with enchantment wizards, and has 'finally' become an Occult Healer Witch in PF2e; my flexibility in performing that process of reinvention per system is higher than some I've seen.
Edit:
I'd even go so far as to say there are two distinct prelusory stages, one where there's a vague notion of playing a game and what it should be like, that culminates in the picking of a system, followed by a second prelusory stage where the system has been selected and characters are being produced. Character concepts can emerge in either or even evenly in both, and that might dictate the directionality of the causative relationship between concept and game-- the difference between having a concept and needing to pick a system that lets you do that, having a concept and picking the best fit to crystallize it in the language of the game that will be played, picking a concept after game selection where you're looking through the options and deciding what to use as expression ex nihilo and prompting an OC based on that, or even hacking a game that has been selected to produce accommodation; particularly since a best-fit for a selection 3-6 people isn't the same as the best fit for 1 person.