Definitely not. Scientific concepts related to cells involve things like cell structure, cell division, and cellular processes. Fanfic has to do with literature created by fans. The two are from completely different domains, and there's no way a cell in the scientific sense could 'absorb' fanfic. It's just not a scientific idea at all.
The phrase 'cell absorb fanfic' is rather strange. 'Cell' can have multiple meanings as mentioned before. Fanfic is a creative form of writing. It could be that someone was trying to be very creative and come up with a metaphorical idea where a 'cell' (again, not clear what kind of cell) is taking in the essence or elements of fan fiction. It could also be a miscommunication or a very niche - specific term within a particular group or discussion that we're not privy to without more context.
No. A cell is a biological unit that functions within the realm of biology. Fanfic is a form of written, fictional work created by fans. There's no biological mechanism for a cell to interact with or absorb fanfic.
Cells are biological units and Sailor Moon fanfic is a fictional story in written form. In a literal sense, a cell cannot absorb a fanfic as they exist in completely different realms. A cell absorbs nutrients, oxygen etc. in a biological context.
One possible fanfic could be about Goku's intense training before the Cell Games. He might be shown pushing his limits in the Hyperbolic Time Chamber, trying out new techniques and forms to defeat Cell. Maybe he discovers a new power level that no one, including himself, expected.
It could be someone from Goku's past who has a vendetta against him and takes advantage of the chaos during the Cell Games. For instance, an old enemy who was thought to be defeated but managed to come back stronger and wants to finish Goku off while he's weakened from the fight with Cell.
It's a really strange concept. If it were possible, perhaps the cell would gain some sort of 'information' in a very odd way. But since cells don't have the capacity for understanding language or stories in the way we do, it's really hard to say what would actually happen.
One common theme is the clash of ideologies. Goku is all about protecting the innocent and having a fair fight, while Cell is more about self - preservation and domination at first.