vtkLinearExtrusionFilter replacement in vtk.js

Is there any replacement for the vtkLinearExtrusionFilter function from Python in vtk.js and is it planned to be added in the future?

No, it does not exist. To my knowledge, there is no plan to add it in the future.
You might want to consider:

  • writing it yourself (or funding it) and make a PR
  • VTK.wasm