This video game creates zero risk that a consumer will buy furniture from the wrong store, so trade dress should be inapplicable. IKEA would likely even lose in court. But as the article points out: legal proceedings ... get really expensive.
This move was pure bullying by IKEA lawyers.
And almost as comical as Nintendo buying rights to a porn movie to prevent their distribution:
No, actually, we decide things based on the law, not based on which side you like more.
I think that would be a fair price to pay for freeing our society from the shackles of pretending you can own an idea, but I get where these executives are coming from.
If you could afford lawyers, you could definitely get away with that game, but it's easier for IKEA to stomp you.