We have a merchant who edits product inventories via importing products CSV in the 'All products' (not 'Inventory') admin panel (https://<STORE>.myshopify.com/admin/products?selectedView=all).
For some reason this does not fire any products/update webhook when only the 'Variant Inventory Qty' CSV column is edited.
Is this expected?
Yes, this is expected behaviour. Inventory adjustments are not counted as product variant updates.