The workers who maintain the website likely are working from home and have a larger workload on them than normal. I could push changes out to my personal website in minutes but the IRS might have a complicated CMS with a long approval pipeline that takes time and coordination to work through.

It's been 3 days...

Edit: I could've sworn the article said it was published on the 17th. Now it says the 20th.

Information on the payment deferral was posted 2 days ago:

https://home.treasury.gov/news/press-releases/sm948

There's a link to that page from the IRS home page.

The filing deadline was just moved to July 15 two hours ago.

Well, I'm guessing there's more of an approval process for updating the IRS website or communicating there than they ... tolerate for tweets, but still, it does seem like too much of a lag, even by the standards of bureaucracy.

The payment deadline was moved 3 days ago, the filing deadline was moved this morning

I could've sworn the article said it was PUBLISHED and UPDATED on the 17th. Now it says it was published and updated on the 20th.

the COVID box to the left of the filing deadline does lead to a page with the proper dates.