If I change a formula or data on one worksheet, do the downstream dependents get updated as they would in excel.
Thanks for your query.
Yes, the relevant cells with data will be updated in the worksheets in the workbook accordingly. If you need to get the calculated results against formulas (for a cell or certain cells) at runtime (or you are rendering to PDF/image format), you will call Workbook.CalculateFormula() method before retrieving the calculated value(s), see the document for your reference:
Hope, this helps a bit.