MenuLinkContent should not define the bundle entity key

Problem/Motivation

Got error page when edit menu item with default_admin theme:

The website encountered an unexpected error. Try again later.

Error: Call to a member function label() on null in Drupal\default_admin\Hook\PreprocessHooks->preprocessBreadcrumb() (line 192 of core/themes/default_admin/src/Hook/PreprocessHooks.php).
Drupal\Core\Theme\ThemeManager->invoke() (Line: 311)
Drupal\Core\Theme\ThemeManager->{closure:Drupal\Core\Theme\ThemeManager::render():293}() (Line: 340)
Drupal\Core\Theme\ThemeManager->render() (Line: 504)
Drupal\Core\Render\Renderer->doRender() (Line: 230)
Drupal\Core\Render\Renderer->render() (Line: 1309)
Drupal\default_admin\Hook\PreprocessHooks->preprocessTopBar() (Line: 523)
Drupal\Core\Theme\ThemeManager->invoke() (Line: 311)
Drupal\Core\Theme\ThemeManager->{closure:Drupal\Core\Theme\ThemeManager::render():293}() (Line: 340)
Drupal\Core\Theme\ThemeManager->render() (Line: 504)
Drupal\Core\Render\Renderer->doRender() (Line: 253)
Drupal\Core\Render\Renderer->doRenderRoot() (Line: 143)
Drupal\Core\Render\Renderer->{closure:Drupal\Core\Render\Renderer::renderInIsolation():142}() (Line: 638)
Drupal\Core\Render\Renderer::{closure:Drupal\Core\Render\Renderer::executeInRenderContext():638}()
Fiber->resume() (Line: 653)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 142)
Drupal\Core\Render\Renderer->renderInIsolation() (Line: 169)
Drupal\Core\Render\Renderer->doRenderPlaceholder() (Line: 764)
Drupal\Core\Render\Renderer->{closure:Drupal\Core\Render\Renderer::replacePlaceholders():763}()
Fiber->resume() (Line: 775)
Drupal\Core\Render\Renderer->replacePlaceholders() (Line: 265)
Drupal\Core\Render\Renderer->doRenderRoot() (Line: 143)
Drupal\Core\Render\Renderer->{closure:Drupal\Core\Render\Renderer::renderInIsolation():142}() (Line: 638)
Drupal\Core\Render\Renderer::{closure:Drupal\Core\Render\Renderer::executeInRenderContext():638}()
Fiber->start() (Line: 639)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 142)
Drupal\Core\Render\Renderer->renderInIsolation() (Line: 113)
Drupal\Core\Render\Renderer->renderRoot() (Line: 260)
Drupal\Core\Render\HtmlResponseAttachmentsProcessor->renderPlaceholders() (Line: 58)
Drupal\big_pipe\Render\BigPipeResponseAttachmentsProcessor->processAttachments() (Line: 45)
Drupal\Core\EventSubscriber\HtmlResponseSubscriber->onRespond() (Line: 246)
Symfony\Component\EventDispatcher\EventDispatcher::{closure:Symfony\Component\EventDispatcher\EventDispatcher::optimizeListeners():241}() (Line: 206)
Symfony\Component\EventDispatcher\EventDispatcher->callListeners() (Line: 56)
Symfony\Component\EventDispatcher\EventDispatcher->dispatch() (Line: 216)
Symfony\Component\HttpKernel\HttpKernel->filterResponse() (Line: 204)
Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53)
Drupal\Core\StackMiddleware\Session->handle() (Line: 30)
Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 118)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 92)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 61)
Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 54)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 753)
Drupal\Core\DrupalKernel->handle() (Line: 34)
Symfony\Component\Runtime\Runner\Symfony\HttpKernelRunner->run() (Line: 32)
require('/var/www/html/vendor/autoload_runtime.php') (Line: 22)
require_once('/var/www/html/web/autoload_runtime.php') (Line: 13)