"This guidance does not change the April 15 filing deadline." This is also solely related to federal income tax payment not the filing.
Form 4868.
Because of the difficult situations many people face right now, it's helpful to have one less thing to worry about. Some people are sick, unemployed/furloughed, trying to save their business, healthcare workers working 80 hour weeks, away from home and unable to travel back, unable to meet with accountant, etc.
I file the 4868 literally every year; I’ve never had any estimate even questioned, let alone overturned, despite sometimes being off by mid-high 5 figures (usually over, sometimes under).
The IRS seems content as long as you’re showing any reasonable intention to comply with your obligations. Everyone is afraid of them because of their power. That’s sensible. My experience (including two audits, one a TCMP audit) is that, while they move at government speed, they are quite reasonable and even helpful to deal with.
In a year where no one has to pay until Jul 15, there is no point in enforcing that clause.
There is benefit to people in pushing the filing deadline even after the payment deadline has been changed as it does reduce the paperwork burden, especially for those who rely on paid preparers.