For some reason, the quaker oats uk website doesn't list it though, perhaps they're new formulations.
I imagine it's used to keep the fine powders (powdered salt or milk powder depending on the product) from caking. If the previous version didn't have any salt, then it might not have needed it.
https://www.britishcornershop.co.uk/quaker-oat-so-simple-hea...
https://www.sainsburys.co.uk/gol-ui/product/quaker-oats-high...
For some reason, the quaker oats uk website doesn't list it though, perhaps they're new formulations.
I imagine it's used to keep the fine powders (powdered salt or milk powder depending on the product) from caking. If the previous version didn't have any salt, then it might not have needed it.