The original incarnation of Mickey Mouse, as portrayed in the 

 on January 1st 2024. This would in principle give anyone the right to portray this character in any way they like without Disney's permission.

However Disney has stated that they believe Mickey Mouse to be so tightly linked to their brand that its representation should be 

 they should be allowed to continue exerting control over its use.

This market will resolve Yes if Disney takes legal action against someone for their portrayal of the Steamboat Willie character in the calendar year following the end of its copyright on January 1st 2024 (i.e. after 1/1/2024 but before 1/1/2025). This legal action does not need to be successful, the only requirement is that it be initiated. For example a lawsuit filed by Disney that later gets thrown out in court would be acceptable.