Behavior in MGNL 6.2 has changed (at least compared to MGNL 5.x):

Use Case:
As an author I want to add a component to an area with only a single available component

Behaviour good old days:

1. Click "Add component"
2. Dialog (of only available component) opens

Behaviour MGNL 6.2:

1. Click "Add component"
2. In new component dialog nothing is selected in "type of component" dropdown
3. Open dropdown
4. Select the component (only option in the dropdown)
5. Click Commit-Action
6. Dialog (of only available component) opens

For us, this happens a lot (Teaser-Group and Teaser, Accordion and Accordion-Panel, Link-Liste and Link ...).