I wouldn't rule it out as a possibility. But what's more likely is︀ that the company is insolvent, deposits are safe, and Peter Schiff is just throwing everything︁ he can at the wall and seeing what sticks.
The way Puerto Rico international banks︂ are regulated is similar to like EU-style EMIs, where they are required by law to︃ hold 100%+ reserves. Calling them banks is arguable a misnomer. Normally, these reserves are ring-fenced︄ for creditors in case the company goes insolvent. I don't know if that's the case︅ in Puerto Rico, though. Haven't read the law in much detail recently.
If creditors are︆ able to dip into deposits, banking regulations (both words used very loosely/generously here) in Puerto︇ Rico are absolutely atrocious , worse than much less reputable jurisdictions. If so, that's the︈ only wake-up call anyone needs to not put any money ever with a Puerto Rico︉ international bank.