Nick here from Shopify. Good question!
I reached out to the Oberlo support team to get more context on this. They mentioned if the supplier sets the price on sale, that is the new price that will be used when you make your orders. The URL would stay the same. However, in the case that the supplier created entirely new product URLs at a discounted price (instead of just setting the existing URLs on sale), it would be considered a completely different product
If you want your existing products to be connected to the new URLs you would need to override the products, which you can learn to do in the guide Oberlo has here. This seems the best way to work around what you are trying to do. Hopefully, it works as a solution!
All the best, Nick
|an hour ago|