You've got 5 teams in the NY, NJ, Mass area. Those cities are not going to be allowed to hold large gatherings until testing has been enhanced to a level that all those who had the disease can been tested to prove they have the antibody. Those states are not even going to end the lockdown rules until that can happen. Those people will then be allowed to go back to work to get some of the local economies going. The actual sound medical practice would be to have a test available for all members of the population and I doubt we see that. Therefore, if you allow people to all of a sudden come out of their shelters and mix with one another once again, you can pretty much assure the return of the problem.
Detroit and Chicagoare also in bad shape. Florida's governor led them into the mess with his idiotic behavior. Every NHL city in the US is having serious problems, but some are better off than others, but the coronavirus guidelines are being followed in all of those states and are responsible for where most of them are standing right now. Ontario and Quebec are not in good shape. California, who believes they are on the lower end of the spectrum due to their quick decision to lockdown are not going to throw that success away in order to hold NBA, NHL, and MLB contests in huge venues with 10's of thousands of fans sitting on top of each other being doted upon by parking attendants, ushers, cheerleaders, concession workers, janitorial staff, etc. These venues are petri dishes for this virus to just sprout wings.
You can bet that the governors of most of the hard hit US locales are not going to prematurely lift their restrictions, particularly on large gatherings, just so they can watch it all happen all over again. Trump has no power to tell them to do anything different. He can say, "Open up!" and they can say, "Pound salt."
A cure or vaccine will have to be found before the general population can SAFELY return to "normal" activity. The vaccine is at least a year away. Who knows about a cure. The real question mark for both of these possibilities is whether or not this virus mutates enough to make the cure/vaccine worthless.
If any of these leagues decide to play, it will be without fans. Even then you will have a mess of people required to make that happen besides the players, coaches, and officials. Do they travel all over the continent. How do you keep the players isolated from the world. How do they eat and where are they quartered? This is a logistical and minute by minute scheduling nightmare. They need to just suck it up, listen to the medical and national health experts, and wait until it's actually proven safe to do this. Listening to wealthy owners and political hacks who want to use the American and Canadian populations for personal and political fodder is ludicrous. This would only be about money and the common people and their lives be damned.