I guess it's to deal with Corona, but it's on new bookings only. I have no idea what they are doing on older reservations. AA is waiving change fees, with the following restrictions.

"Terms and conditions
If you purchased a ticket on American Airlines between March 1, 2020 at 4:30 p.m. CT and March 16, 2020 at 11:59 p.m. CT, you may change your flight once without paying a change fee if the change is made at least 14 days in advance of your outbound travel date. Tickets must be purchased for travel between March 1, 2020 and January 26, 2021."

I have no idea whether other airlines are doing similar things, just was looking at the AA website for something else and noticed this.