I never saw this formally announced by Google; and our ecommerce clients were never notified about this change, so I just want to make sure everyone sees this update.
This is a quote from the agency newsletter:
Sunsetting Product Extensions
Product Extensions will be sunset for all enabled campaigns and will be removed from the campaign creation flow on May 20th. With increased Product Listing Ads adoption, Product Extensions have become a less relevant way to display retail products. If you have Product Extension Ad, it will continue to run as a text ad.
After PLAs were launched, Google removed the image from the extension and changed the extensions so it just showed a line of text and a price. Without the compelling image, and the additional of image filled PLAs – our CTRs on product extensions has slowly declined over the past year.
It looks like you can spend your time working on your PLA structure and making sure you are getting good PLA results as that looks like it will be the future monetization of Google Shopping.