CSS Display says

The following features are at-risk, and may be dropped during the CR period:

• Application of ::first-letter in the presence of run-ins
• display: run-in
• All two-keyword values of display and display: inline-list-item

It says "two-keyword values". But display admits the following three-keyword values:

• list-item block flow
• list-item block flow-root
• list-item inline flow
• list-item inline flow-root
• list-item run-in flow
• list-item run-in flow-root

I think these should also be at-risk. I would say that all multi-keyword values of display are at-risk.