Update 3/19:
The CDC now recommends cancelling events of more than 50 people for the next 8 weeks, and Major League Soccer has responded that they will extend the postponement of matches for the 2020 season.
The press release did not indicate how long that postponement would be for, but did say “MLS remains focused on playing the entire 2020 season and is evaluating all options, including pushing back the end of the season and playing MLS Cup in December, as the league did prior to the 2019 season. The league is also identifying other available dates.