This is the Anthropic press release from last year saying they will use Trainium: https://www.anthropic.com/news/anthropic-amazon-trainium

This is the AWS press release from last month saying Anthropic is using 500k Trainium chips and will use 500k more: https://finance.yahoo.com/news/amazon-says-anthropic-will-us...

And this is the Anthropic press release from last month saying they will use more Google TPUs but also are continuing to use Trainium (see the last 2 paragraphs specifically): https://www.anthropic.com/news/expanding-our-use-of-google-c...