Background of the issue:
I am running some tests to improve the hreflang implementation on our website. Currently, our URLs in other languages end with /?lang=es for Spanish, but I’d like to change this to a format like /es/, as it is better for SEO. After making the changes, everything seems to work correctly.
Symptoms:
I’ve noticed that the old URLs (e.g., /product/g778-stepper/?lang=zh-tw) still function alongside the new URLs (e.g., /zh-tw/product/g778-stepper/).
Questions:
Will the old URLs continue to work indefinitely or might they stop working over time?
Is it necessary to implement redirects for the old URLs?