As said it is one of the better funded legal teams in the world and is very proactive in intervening v.quickly. Disney is infamously trigger-happy with litigation when it comes to copyright and knows the rules regarding it better than probably anyone else. In 1989 they sued the Academy of Motion Pictures for use of the Snow White character at the Oscars! If they can't win in court they also have a huge team of lobbyists to change the law to ensure they still get what they want.

Disney is so large and encompasses so much that they need experts in almost every field who can all call on each other for advice. They are also one of the largest possible potential targets for lawsuits. They have loads of money and an image to protect. The best way to save themselves constant lawsuits or settling to protect their image was to repeatedly demonstrate you never beat the Mouse in court.

They also have a corporate culture of perfect realisation of vision dating back to Walt Disney himself. If Walt wanted something you couldn't tell him no - you were expected to find out how you could achieve EXACTLY what he wanted. Naturally this often requires very specific legal knowledge to circumvent whatever restriction you face and historically they have made some outstanding wins in court. If Disney wants non-regulation yellow lifeboats for their cruise line then they will prove that that shade of yellow matches international standards for visibility and lobby for exclusive rights to use that colour. So Disney gets Mickey-Mouse shoe colour lifeboats, a tiny detail few will care for or notice but Disney took the effort to get their way.

The cases I'm most familiar with regard the theme parks. Just acquiring the land for Walt Disney World and the rights over it they did is enough for them to sit on their laurels but the parks have also won a myriad of personal injury suits - some of which they probably shouldn't have. If they genuinely think they will lose it gets settled out of court with an NDA. Most recently they curb-stomped DeSantis regarding land management in Florida.

Not quite true. Steamboat Willie isn't set to enter public domain until Jan 2024.

Disney has been using the likeness of Mickey in Steamboat Willie as the logo for Walt Disney Animation since Tangled in 2010 with the goal of establishing trademark for that version of Mickey.

They have been using red-pants Mickey as part of the logo of The Walt Disney Company since (I think) the 50's so their case there is stronger.

They are hoping between the two that any other style of depicting Mickey Mouse will be close enough to create 'brand confusion' with one of the versions and hence be able to be litigated against.

Not guaranteed to work but Disney has one of the best legal teams.