The only interesting thing here is that they’re partnering with Microsoft. Palantir has been a government contractor since the very beginning. Maybe - maybe - they’ve got their workflows standardized by now (before every single thing they did was a bespoke engineering effort).
If the article is serious about the TS classification (and not just saying “top secret” to get the idea that it’s classified at some level across to the civilian reader) it means they’re re-engineering something to work in the TS side of Azure Classified Cloud and possibly making it available on JWICS.