A lot of Disney products are just “disnified” public domain. You can make a Snow White, Cinderella movie tomorrow. Jist can’t use Disney’s version.
Those copyright laws you mention were mostly changed by congress, specifically for Disney. Next congress should repeal all of them.
The late head of the MPAA, Jack Valenti, famously said regarding copyright protection, "We have friends on both sides of the aisle."
It's true. Sonny Bono was a Republican.
And the Big Studios, Record Companies, Publishers spread a lot of money around, to both parties, whenever copyright issues are considered in Congress. Really, they're rarely even debated. Both parties have historically done Big Media's bidding.
Even so, I don't think Big Media will get yet another copyright extension. But there won't be any rollbacks.