implementation-status.md: Clarify initial_team_index is expected to appear in forthcoming PRIF 0.6

Author: bonachea

docs/implementation-status.md

@@ -89,9 +89,9 @@ are accepted, but in some cases, the associated runtime behavior is not fully im
 | `prif_image_index`                               | **YES** |  |
 | `prif_image_index_with_team`                     | **YES** |  |
 | `prif_image_index_with_team_number`              | *partial* | no support for sibling teams |
-| `prif_initial_team_index`                        | **YES** |  |
-| `prif_initial_team_index_with_team`              | **YES** |  |
-| `prif_initial_team_index_with_team_number`       | *partial* | no support for sibling teams |
+| `prif_initial_team_index`                        | **YES** | expected in PRIF 0.6 |
+| `prif_initial_team_index_with_team`              | **YES** | expected in PRIF 0.6 |
+| `prif_initial_team_index_with_team_number`       | *partial* | expected in PRIF 0.6, no support for sibling teams |
 
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