Board Thread:Questions and Answers/@comment-4894381-20130619161615/@comment-4848837-20131113233408

The DNA was not in the Omnitrix, and what occurred with Clockwork was a pretty unique circmcumstance (pretty much a 99% chance of that not happening again for Terraspin). That would also be quite interesting considering Ben should've recognized that member of Terraspin's species when Galapagus debuted in Escape From Aggregor.

The Omniverse team can work something one time, but doing it again (especially with Terraspin) might prove to be difficult considering all the retconning that would need to be done to accomplish it.