Apply suggestions from code review

Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>

Author: johnslavik

Doc/library/typing.rst

@@ -2530,7 +2530,7 @@ types.
    .. deprecated-removed:: 3.15 3.20
       It is deprecated to call :func:`isinstance` and :func:`issubclass` checks on
       protocol classes that were not explicitly decorated with :func:`!runtime_checkable`
-      after subclassing runtime-checkable protocol classes. This will throw
+      but that inherit from a runtime-checkable protocol class. This will throw
       a :exc:`TypeError` in Python 3.20.
 
 .. decorator:: runtime_checkable
@@ -2609,7 +2609,7 @@ types.
    .. deprecated-removed:: 3.15 3.20
       It is deprecated to call :func:`isinstance` and :func:`issubclass` checks on
       protocol classes that were not explicitly decorated with :func:`!runtime_checkable`
-      after subclassing runtime-checkable protocol classes. This will throw
+      but that inherit from a runtime-checkable protocol class. This will throw
       a :exc:`TypeError` in Python 3.20.
 
 .. class:: TypedDict(dict)

Lib/typing.py

@@ -2022,7 +2022,7 @@ def __subclasscheck__(cls, other):
                     f"{cls!r} isn't explicitly decorated with @runtime_checkable but "
                     "it is used in issubclass() or isinstance(). Instance and class "
                     "checks can only be used with @runtime_checkable protocols. "
-                    "This may stop working in Python 3.20."
+                    "This will raise a TypeError in Python 3.20."
                 )
                 warnings.warn(depr_message, category=DeprecationWarning, stacklevel=2)
             if (
@@ -2062,7 +2062,7 @@ def __instancecheck__(cls, instance):
                 f"{cls!r} isn't explicitly decorated with @runtime_checkable but "
                 "it is used in issubclass() or isinstance(). Instance and class "
                 "checks can only be used with @runtime_checkable protocols. "
-                "This may stop working in Python 3.20."
+                "This will raise a TypeError in Python 3.20."
             )
             warnings.warn(depr_message, category=DeprecationWarning, stacklevel=2)