I can't follow all the chemistry but this seems like the takeaway, from the Nature paper (open acccess!):

> Regardless, confirmation of macromolecular organic matter supports the possibility that future optimized TMAH thermochemolysis experiments can liberate ancient biosignatures preserved in macromolecules on Mars (if present). The broad structural variety of organic molecules observed in situ from surface materials suggests some chemical diversity is preserved in ancient Martian sediments despite >3.5 billion years of diagenesis and radiation exposure.

Macromolecules, not just "organic" (which, reminder, does not mean "biological"). It seems like you can still get macromolecules abiotically, but it's a little more tantalizing.