The analysis they present doesn't require the integration of foreign RNA. 2019nCov has a SPRR motif, where other viruses has similar motifs (SRRK, KNRR, TPRS...

The analysis they present doesn't require the integration of foreign RNA. 2019nCov has a SPRR motif, where other viruses has similar motifs (SRRK, KNRR, TPRS...). It can be explained with mutations, and in fact they talk about convergent evolution.