This doesn’t work for all Lego units that go retiring. However should you use this technique you’ll be able to make sure that these units shall be retiring.
Set up in your Iphone or Android system the app”Lego constructing instruction“. Seek for the Lego set that you just suppose that can retire.

I take advantage of for instance the Lego 40440. As you’ll be able to see the apps says it’s Retired.

The Lego.com websites says that’s nonetheless accessible.

Anther instance is the 71755 Temple of the Infinite Sea.

And add Lego.com this Lego set remains to be accessible.
We will be happy to hear your thoughts