Porngame- doesn't need canonicity or a possible timeline..
Not maintaining reverence for it's source material and verisimilitude is one of the biggest red flags for a fan work, including porn games. Once you break link with the canon of the source material that alters the expectations of the readers about how the source material will be used going forward in a way that can't really be recovered from. It diminishes the value of being a parody game in the first place. You can't depend on knowledge about the character from the source material until the game reasserts it. It can work for some games, but for a game that has already put so much effort into being faithful, I would be really disappointed to see characters inexplicably aged up, in situations they have no reason to be in, or brought back from the dead. It only takes a little bit of contrivance to avoid it in most cases though. Good fan service isn't just showing a character, it's making proper use of them to build off of their official depiction.
For dead characters, the setting does have spirit mediums. Maybe Bluecorp already has one on the payroll. It'd be a shock to find a card of Mia and have to figure out how it's possible and why she would agree to it.