You are right. I did install Rosetta for sure and have the same files as you mentioned. I did the installation through custom install enabling Rosetta manually in the installer and did not lose anything, as expected.
3.1 GHz 13" MacBook Pro 2015, 8 GB RAM, OS 10.11.2, Office 2011, TimeWarner Cable
2.8 GHz Xeon Mac Pro 2010, 16 GB RAM, OS 10.11.2, Office 2011, LAN