That's arguably the goal of [Pluto.jl](https://github.com/fonsp/Pluto.jl). It's a (Julia-specific) reactive notebook that automatically updates all affected cells and has no hidden state.
Please no. Excel is great when it stays within its lane and use case and doesn't try to be everything. Jupyter is okay-ish is some places but in general is way overused. Mixing them together would be a move in the wrong direction and a bit of a mess.
There's been a few projects in this space (PySpread is the first that jumps to mind), but also, not too long ago (last year maybe?), MS was investigating making Python a first-class inhabitant of Excel, so might already be in the pipeline.