It definitely is possible , especially for a catholic family. I suppose his father could have been named Emil and it got changed Emelyan in official records where they tend to put more common Russian names. Depending on fathers name interpretation the patronymic would be Emilyevich for Emil and Emelyanovich for Emelyan. Emilich sound like shortened non-formal version of Emilyevich that for example friends would use.

My family is also Molokan, and I have a few Shubin ancestors from the same village as Vasilii Emelyanov, Voskresenovka. I've even spent some time researching his particular family. People's patronymics were often spelled differently after emigrating. I think they used spellings in Latin script that approximated how they pronounced it and syllables were lost in transliteration. Often Mikhailovich is spelled Mihailich after emigrating, for example. The name Emil was not used among this Molokan community but Emelyan was. So Emilich would almost definitely be Emelyanovich or Emelyanov in Russian. In general, people converted to the Molokan faith from the Russian Orthodox church (not Catholicism).