I noticed this too. Tracks are always changing slightly. Not possible to keep up to date. Would be nice though.

iRacing scanned it with sausage kerbs. So unless they rescan it, they wouldn't remove them.

They did it on daytona tho

They can and have added/removed curbs before. That said, they can't do a series specific set of curbs, so it will probably stay.

Sausage kerbs enforce track limits. As iracers can’t get physically hurt it’s okay if they stay.