This update wasn't the BERT related. John Mueller himself said it wasn't likely to be BERT:
https://www.searchenginejournal.com/john-mueller-november-2019-update/335791/#close
BERT was only about a better understanding of search intent with natural language, for example, if stop words are included. You can read about it here:
https://www.blog.google/products/search/search-language-understanding-bert/.
A simple word can change the meaning of a sentence, so BERT now reads the whole sentence as a query, rather than processing each word in turn. It's not done away with keyword research and how you should produce content and answer questions. It just means that Google will be better able to understand what someone is asking.