here are the two answers to the original questions:
1) No, you are not required to claim your dependents. I agree with this.
2) Yes, they can claim themselves if they need to file a tax return. I agree with this However, the nuance is that as part of the process, there is a SEPARATE question that asks if someone else can claim them. It has implications to how the standard deduction (among other things) are calculated. In either case, they can still claim themselves; the financial benefit of claiming yourself is just different depending on the answer.
