address PR review comment

sqlglot/dialects/dialect.py

@@ -1570,23 +1570,25 @@ def normalize(identifier: t.Optional[exp.Identifier]) -> t.Optional[str]:
         targets.add(normalize(alias.this))
 
     for when in expression.args["whens"].expressions:
-        # only remove the target names from the THEN clause
-        # theyre still valid in the <condition> part of WHEN MATCHED / WHEN NOT MATCHED
-        # ref: https://github.com/TobikoData/sqlmesh/issues/2934
-        then = when.args.get("then")
+        # only remove the target table names from certain parts of WHEN MATCHED / WHEN NOT MATCHED
+        # they are still valid in the <condition>, the right hand side of each UPDATE and the VALUES part
+        # (not the column list) of the INSERT
+        then: exp.Insert | exp.Update | None = when.args.get("then")
         if then:
-            then.transform(
-                lambda node: (
-                    exp.column(node.this)
+            if isinstance(then, exp.Update):
+                for equals in then.find_all(exp.EQ):
+                    equal_lhs = equals.this
                     if (
-                        isinstance(node, exp.Column)
-                        and normalize(node.args.get("table")) in targets
-                        and not isinstance(node.parent, exp.Func)
-                    )
-                    else node
-                ),
-                copy=False,
-            )
+                        isinstance(equal_lhs, exp.Column)
+                        and normalize(equal_lhs.args.get("table")) in targets
+                    ):
+                        equal_lhs.replace(exp.column(equal_lhs.this))
+            if isinstance(then, exp.Insert):
+                column_list = then.args.get("this")
+                if column_list is not None:
+                    for column in column_list.find_all(exp.Column):
+                        if normalize(column.args.get("table")) in targets:
+                            column.replace(exp.column(column.this))
 
     return self.merge_sql(expression)