Why doesn't "add device" include the HomePod anymore? Only HomePod Mini is all over, but no older HomePod. Now it appears no longer compatible?

Why doesn't "add device" include the HomePod anymore? Only HomePod Mini is all over, but no older HomePod. Now it appears no longer compatible?

In calling support, they had me "remove" the HomePod from the Home App hoping to "reset" it, but... then it couldn't be reset and re-added to the Home App. What's with that? I have the original packaging, but it doesn't include the 9 digit code that they want you to use to manually add it. Anyone encountered this?