That doesn't formally answer the question, though the fact that they will respect all withdrawals does suggest that they are unlikely to be insolvent. For example, they could be insolvent but allow withdrawals up to the last 19k bitcoins.
I don't mean to suggest that they are not solvent; I am only pointing out that the language doesn't seem to perfectly answer the question.
I don't mean to suggest that they are not solvent; I am only pointing out that the language doesn't seem to perfectly answer the question.