private boolean unregisterUnsupportedClient(AuthenticationExpiredException expired) {
    if (getProxy().getVersion().isNewerThanOrEqualTo(RE_AUTHENTICATION_START_VERSION)) {
      return false;
    }

    logger.warn(
        "Authentication expired for a client with a version less than Geode 1.15. Cannot re-authenticate an older client "
            + "that has a server to client queue for CQs or interest registrations. "
            + "Please upgrade your client to Geode 1.15 or greater to allow re-authentication.");
    synchronized (_stopDispatchingLock) {
      pauseOrUnregisterProxy(expired);
    }
    return true;
  }
for old client, don't wait for re-auth but unregister this proxy completely.
geode-core/src/main/java/org/apache/geode/internal/cache/tier/sockets/MessageDispatcher.java