I think when the league and maybe also the government are certain that things are now fully out of control and they cannot guarantee the safety of the players, then games will be postponed till further notice. But as long as games are still ongoing,(though in an empty stadium)then it's is still very much safe for the players to go out there and do their job and no doubt they will.
This virus is taking out some of the fun this league has had since the beginning, it's sad that things have to get to this stage, but we can hope that very soon all this will end and the beautiful game continue without anything to worry about.
With the open borders between Italy and other nations in Europe I believe sooner or later the virus will spread out over all European nations. The severity of outbreak locally will depend on government reactions (fast or slow, seriously or mildly) with outbreaks and how they trace suspected cases, people who have close contacts with confirmed cases and prevent massive spread in communities. The bad news is weather still cold in Europe, that is good condition for the survival of virus.
As this virus is spreading its really shocking because today I was reading Italy is now in top five countires those are infected with this Iran is also in some serious trouble as few high profile peoples also diagnost with this virus so if authorties sure then can handle things then surely they can allow teams to play if they feel its not good then there is no panic with suspend games.
If Italy can not control the outbreak at the north and let it spreads over the nation, Serie A will be postponed because there is no barriers and guarentee that players won't be infected by the virus. The worst scenario is when not only Serie A but also most or all soccer leagues in Europe will request all matches in closed stadiums or suspende all matches till the endemic (or pandemic) halts or reduces its severity.
