If the objective is curation, that could easily and more effectively be done via an online feed

Well, it is, just like every other CBC Radio program. Podcasts is the business they are in.

The OTA broadcast is there merely to stream the same content out to legacy devices which are not compatible with the modern feeds. If it were a campus/community run venture, even if it were a commercially run venture, they would no doubt only offer the feed, but as they have taxpayer support they are also able to accommodate those who are unable or unwilling to adopt newer devices.

Now, maybe there is a case to be made that the program isn't worth producing for any medium, but I don't have listenership data to delve into that. It would not surprise me if a lot of people enjoy it, though. It seems far less niche than Writers and Company. Assuming it is well received, that is a pretty good reason to produce it.

she kind of was the show in a sense.

Fair. Hard to lament someone wanting to move on with their life, though. That show has been on the air seemingly forever. It is not like Podcast Playlist is displacing it. They have been produced in parallel. Its actual replacement is yet to come – and it might be even better!