There have been efforts to tag keywords in arXiv [0] and to identify sections of articles [1]. A conference on Mathematical Knowledge Management [2] was held last week; some participants have already been analyzing ArXiv.

Hopefully integration with Kaggle expands the number of teams taking advantage of the knowledge in the corpus.

[0] http://sciencewise.info/ [1] https://github.com/OMdoc/OMDoc/wiki/PhysML [2] https://cicm-conference.org/2020/cicm.php