I don't think that's the best bet, though. I think we can both agree that whatever injury Soroka had was not one that's going to destroy him; while shoulder strains are not great, they're pretty normal stuff pitchers handle. Long term, they can suggest arm issues, but while it probably isn't as benign as a hangnail or a blister, this isn't a UCL issue. Considering the velocity is back, structurally and health wise, we should assume he's fine for the playoffs.
So, then we have to ask "why did he struggle post injury?" and I think rust and a bit of a pitching philosophy change is occurring. Look at where his fastball is landing now compared to before. The first is leading up to the TDL:
And now since:
We can see there is something different happening here. Whether or not that's because it's a mechanical thing or a new process is not really able to be seen there. But we can see things are very different right now.
Regardless, I think the Cubs think there's a bit more here than you do. And considering that I don't think Assad and Civale have a lot of separation, Soroka probably offers a different option when things are right.