I put the sources above. If you read through, you see that not only did the numbers change but also that he specifically made predictions based on a scenario where zero attempts to mitigate infection were taken.
The first time I clicked on that twitter link it only showed two tweets and not that whole thread. The site was probably under unusually high load in the immediate wake of Trump's speech and the NBA news.
After reading the entire thread, he didn't say "zero attempts to mitigate infection". He said "without effective controls". He also said " Increasing evidence that the extremely intense control measures in China have reduced transmission while they are in force. As long as such intense control measures are in place it is possible to imagine keeping the number infected well below 40%. I don't believe most countries (maybe not even China) can keep such controls for months or a year, the minimum time frame for potentially having a vaccine. But even more moderate ones if effective could reduce incidence considerably". Not even Italy has gotten to the extreme measures that China was implementing. Also if you read his more recent tweets you will see that he thinks the European travel ban is futile.
Overall it sounds to me like that 20% number that I have been using since your first post is the updated number based off of our current mitigation strategy. I don't see any indication that he thinks that number is too high given the current path. Once again, I am completely open to learning otherwise if you have something that you can point to that clearly states otherwise.
