Rainbow Six Extraction is built from Siege's DNA but seems to be missing some of the best key strands.
Jordan got to spend 6 hours of hands on time with Rainbow Six Extraction playing two maps located in San Francisco and New York. One stand out note is that the maps are substantially larger than their Rainbow Six Siege predecessors but they are way more horizontal compared to those found in Siege, where verticality plays a larger role in both map design and navigation. This is only based on the two maps listed above.
In Extraction, several of Rainbow's operators are recruited to join a special team tasked with combating the parasitic alien Archaeon threat that's spread throughout North America. That mission takes you to four different zones, each of which are divided into three maps, and each of those maps in turn are cut into three separate regions. So, for example, the San Francisco zone is split into the Tenderloin, Enterprise Space Foundation, and Apollo Casino & Resort maps.