Remakes happen all the time. We've also seen several games get additional content after the original developers either completed or abandoned their work.
Witch Trainer Silver is a modded version of Witch Trainer developed by a group unrelated to Akabur, the original creator. Akabur released his game as a completed work and moved on to other projects. Silver is still a very popular title and just received another big content update today.
Lab Rats 2: Reformulate is a modded version of Lab Rats 2 developed by a group unrelated to Vren, the original creator. Vren abandoned his project before finishing it and has seemingly moved on from game development, or at least stopped communicating to his fans. Reformulate is as popular as the original game was, perhaps with renewed interest due to the various different mod branches folks are working on (like the GenAI mod for example)
Sexbot Restoration 2024 is a remade version of Defective Sexbot Chop Shop developed by someone unrelated to Radnor, the original creator. Like Vren, Radnor also abandoned his project before it was finished and is now MIA. squirrel24 has taken over development in the remade game and has even offered to support modders by working to port their content over from DSCS to SR24.
This is only brushing the surface, too. Searching all of F95zone for "remake" and filtering results so that only game threads show up yields 12 pages of results. This is really rather common in the world of porn games, and about half of the posts I clicked from those results were actually fan recreations of previously completed (or abandoned) titles. Anna's Exciting Affection, Urban Demons, Big Brother, Manila Shaw, Lily of the Valley, and on it goes. These were extremely popular games, both the originals and fan versions.
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allm - My recommendation: Change the title to make it obvious what your project is so there's no confusion. Call it something like "The Regional Manager: Unofficial Fan Remake" (or something more clever than that, lol)
I think the most important thing is to make it clear to others that your version is unofficial and not the original. As long as you do then I think you should be fine.
I would definitely recommend making a separate development thread for your dev discussions though, or at least a separate game thread for your modded version. I wouldn't recommend posting your work in this thread directly because it'll get lost in these 160ish pages of discussion and it could also confuse newcomers.
Good luck with the project, I'm curious to see what you've got up your sleeves.