Yes, they have, but it is writing assistant.
And this is WordPress plugin page.
These are the features of this plugin
- Overall score – checks the article’s general quality calculated according to metrics such as readability, text length, and target keywords.
- Readability score – evaluates your text’s difficulty based on the recommended Flesch-Kincaid reading-ease score. You will get recommendations for sentences and words that need improvement.
- Target keywords – shows recommendations regarding the given keywords, their volume and their difficulty.
- Recommended keywords – shows semantically related keywords, that should also be added to your text.
- Tone of voice – make sure that your writing is consistent with the desired level of formality.
- Plagiarism – validate that your writer has submitted original content.
- Linking – check your links for possible errors and problems.
So, if you want to find SEMRush for keyword research in WordPress SEO plugins, I am afraid there is not. If you want to do keyword research, you should do it on their site.
Hope it helps. You may follow me for more about SEO from a programmer point of view.