update minCompatibilityVersion range.

Signed-off-by: Siyuan Zhang <[email protected]>

keps/sig-architecture/4330-compatibility-versions/README.md

@@ -276,8 +276,8 @@ release for features to settle in as is typically needed for rollback support.
   - In alpha we intend to support:
     - `--emulation-version` range of `binaryMinorVersion`..`binaryMinorVersion-1`
   - In beta, we intend to extend support to:
-    - `--emulation-version` range of `binaryMinorVersion`..`binaryMinorVersion-1`
-    - `--min-compatibility-version` to `binaryMinorVersion`..`binaryMinorVersion-1`
+    - `--emulation-version` range of `binaryMinorVersion`..`binaryMinorVersion-3`
+    - `--min-compatibility-version` to `emulationVersion`..`binaryMinorVersion-4`
 
 ### Non-Goals
 
@@ -316,7 +316,7 @@ version be <= the kube-apiserver binary version, it must also be <= the
 
 #### --min-compatibility-version
 
-- Defaults to `binaryVersion-1` (matching current behavior)
+- Defaults to `emulationVersion-1` (matching current behavior in emulation mode)
 - Must be <= `--emulation-version`
 - Must not be lower than the supported range of minor versions (see graduation
   criteria for ranges). If below the supported version range the binary will
@@ -338,7 +338,7 @@ rules be defined in terms of compatibility and emulation versions:
 
 - kubectl:
   - Previously: `1.{binaryMinorVersion-1}`..`{binaryVersion+1}`
-  - With this enhancement: `{minCompatibilityVersion-1}..{emulationVersion+1}`
+  - With this enhancement: `{minCompatibilityVersion}..{emulationVersion+1}`
 
 ### Changes to Feature Gates
 
@@ -876,7 +876,7 @@ We intend to have this up and running for Beta
 
 - Initial cross-branch e2e tests completed and enabled
 - Emulation version support for N-3 minor versions
-- Compatibility version support for N-3 minor versions
+- Min compatibility version support for N-4 minor versions
 - Clients send version number and servers report out-of-allowance skew to a metric
   (Leveraging work from KEP-4355 if possible)
 - All existing features migrated to versioned feature gate - [kubernetes #125031](https://github.com/kubernetes/kubernetes/issues/125031)