So, going to share a bit of a hot take here. 
I want to start by being VERY CLEAR that this is my attempt to be honest and not to be hostile. I love Apollo and the products this team pumps out!
Iāve been a massive fan of federation and my team was a very early adopter of it. I understand the advantages/disadvantages of managed versus unmanaged but thus far we have gone with unmanaged for three reasons:
1.We like the dynamic nature of being able to deploy a single microservice and the changes in schema be picked up immediatelyā¦ especially when doing local development. Itās nice to not have to restart services.
2.We donāt have any plans to utilize Apollo Studio for a variety of reasons.
3. There isnāt a stable, well-documented way to do home-grown managed federation.
What worries me about this deprecation, and the direction Iāve seen Apollo seeming to go, is it seems that there is a push for āuse our paid services or elseā. This is a major step back from the typical monetized open source model that I typically see where it is more āHereās an awesome open source product. Here are additional features/functionality/support that you CAN use to add additional value.ā
This change to remove serviceList, with a lack of stable and documented way to NOT use studio, is anti-open source, in my opinion, because it leaves zero options for consumers who are not in the Studio ecosystem.
For this to be āfairā open source product that doesnāt back consumers into a corner and that doesnāt leave consumers stranded, consider eitherā¦
- Leave serviceList as is or
- Provide VERY CLEAR alternatives for consumers not using the Studio ecosystem.
Again, trying to provide this outside prospective as a consumer who loves the library. 