Can IRS intercept your rebate if you owe federal or state back taxes, or other debts?

No, unless. There is one exception to the “offset bypass” rule: People who are so delinquent in child support payments that they have been “certified” by a state agency.

Some interesting history can be found in a blog post today by Carlton Smith, who has extensive experience with low-income taxpayer clinics and in retirement volunteers at Harvard.  He also discusses who gets the rebate in bankruptcy cases.  

https://procedurallytaxing.com/so-how-will-the-recovery-rebate-refunds-work-this-time-part-ii/