This is a bit misleading: FTX US Derivatives LLC, formerly known as LedgerX, is indeed a wholly owned subsidiary of FTX US (acquired Oct 2021). However, at an operational level, it is an entirely separate entity and will probably continue to operate as such (likely reverting to DBA LedgerX). The CFTC licensure was established well before the acquisition.

It's debatable whether you can pin some kind of blame on the CFTC for failing to regulate the entirety of FTX's international operations when they were 100% decoupled from the operations of the one entity that was actually licensed. This article, while surely well-intentioned, is still mostly just grandstanding by a political lobbyist.