At this point, there hasn’t been any response or comment from either Google or Twitter on the matter.
It’s been quite a while since we last saw Google indexing tweets, as the relationship between the two companies ended in 2011. The falling out was a result of Google killing Real Time Search and Twitter ending access to the firehose. Ever since, Twitter updates via the search engine has been spotty since Google has had to crawl Twitter in order to index tweets.
Read more about the deal on Marketing Land. To learn more about the history of the Google-Twitter search relationship, read this by Danny Sullivan: Three Years After Breaking Up, Twitter Wants Back The Google Search Love It Once Had