They've been using keyword checks to filter candidates for a long time. They apparently don't like it when things are turned back on them.

I've seen some seriously awful resumes get through the first level filtering. As long as they hit the keywords, nobody cares about formatting or coherency. Those candidates are usually terrible in other ways, so this system ends up wasting the time of people higher up the chain who have other things to do than interviewing.

You're supposed to review the generated cover letter first.