i don't think erica doing that web series.shooting started and all cast finalized..
The way erica is getting fitness training I feel erica is doing something army girl or police type or some other fitness related role ..may be some thing else but not this..
Yeah from her training it looks like she is doing something which requires lot of physical strength. And if Eri was part of 2020, then they would have announced it I think to create a buzz as most of the characters in that show are announced and have started shooting. Also, my point is ki EK hyping her debut would not be unless she has a pivotal role in the show.