What is the point of "linking" my GitHub in Azure Container Apps?

Inside ACA, I went to Continuous Deployment, and logged in with GH, enabled Admin login on ACR and let it auto create an Actions file and SP, and User-Managed Identities and create roles on ACR, ACA, ACE, and all their RGs.

So lots of magic there and its done and works.

However, in ACA I see that the GH stuff is "connected" and I must click "disconnect" to change anything there. Why does that matter? GH Actions is now deploying from outside Azure using this Action. So why exactly does ACA need to know anything about GitHub?

Additionally:

The generated Action was full of variables that were broken and had underscores like:

```yaml
- name: Build and push container image to registry
uses: azure/container-apps-deploy-action@v2
with:
appSourcePath: ${{ github.workspace }}/App1-Web
_dockerfilePathKey_: _dockerfilePath_ # <------------------------------------ ?
_targetLabelKey_: _targetLabel_ # <------------------------------------ ?
registryUrl: app1.azurecr.io
registryUsername: ${{ secrets.APP1_REGISTRY_USERNAME }}
registryPassword: ${{ secrets.APP1_REGISTRY_PASSWORD }}
containerAppName: app1
resourceGroup: App1-ACA-RG
imageToBuild: app1.azurecr.io/app1:${{ github.sha }}
_buildArgumentsKey_: | # <------------------------------------ ?
_buildArgumentsValues_
```