Note in the ad specs it calls for 20A independent circuit on all washers. As a "recommendation" though, not a requirement. The alternative is resetting the shared breaker when the combined loads exceed the branch rating.
Normal motor start current is twice the run current, though only roughly half a second. That's plenty to trip a breaker that's already running a window air. And that's the problem with older bungalows. Or even bungahighs. Typically, not a code violation unless the wiring is renovated without bringing it up to code. Which costs thousands, natcherly.
But electrical fires don't care whether the violation is waived or not. You will just have to make some other arrangement to get power to both those appliances. Or never use both at the same time.
Optimally your solution will not involve extension cords. If only option, use the shortest and biggest gauge you can get. While you're at it, find out what the microwave shares a breaker with. Hopefully not the fridge.
There is almost certainly nothing wrong with the Maytag.