Because paramInfo is missing it leads to creation of "dirty diffs" when editing invocation of a template.
I recorded a video that shows this problem: http://cl.ly/1T38012d0j1a It is based on this two articles:
https://www.mediawiki.org/w/index.php?title=User:Inez_Korczy%C5%84ski/Test1&oldid=1960800
https://www.mediawiki.org/w/index.php?title=User:Inez_Korczy%C5%84ski/Test&oldid=1960799