@scottjenson dunno, maybe we should bring the "Interaction Designer" back? (I liked 'interaction' better than the vague and hard-to-defend 'experience' anyway)
I think the decision to remove app name and icon is separate from the new activities/workspaces indicator.
For knowing what app I am in: In MS Windows e.g. there is no separate indicator either and it seems to work by the "whatever is on top"-heuristic plus subtle hints like lower contrast on inactive windows.
I have looked at a lot of logos in open source projects. The problem that is most common and easiest to check is that logos only work when they are big.
Try if the logo still looks good and is easy to recognize when its small – max 32x32px.
Take this logo for a collaborative map editor (no shaming, I created this, no real projects harmed):
In typical fashion the creator combined several symbolic elements: People stretching out arms also frame a map with a position indicator (could have added a pencil, too)
If you want an example: The logos of bigger companies and services in your browser tabs are usually professionally designed and this is something professionals check for (they also create a small version for that purpose, so their tab-icons look even better than just their small logo, but the check still applies)
What might logo design even worse for #opensource projects is that:
1) code production is often modular and that idea is extended to other media
2) the logo must be argued for using largely written communication
The result is that piling obvious symbols on symbols: "The collaboration is people reaching out hands, there is a map and the pencil stands for editing it"