Everybody loves Disney's (DIS -2.68%) new streaming service, and for now that's been more than enough for the media giant to beat the market in 2019. The buzz was strong ahead of the mid-November launch of Disney+, and it delivered when The Mandalorian became the platform's first hit series. 

Disney will wow investors when it reports impressive subscriber and engagement numbers next week. The market will overlook the potential weaknesses elsewhere, and it could possibly even dismiss the warnings of how coronavirus will eat into its theme parks and theatrical releases in the current quarter. But the honeymoon may not last as 2020 plays out. Let's go over three ways the initial success of Disney+ can sting the media giant's other businesses. 

Mickey and Minnie on a float during an afternoon parade.

Image source: Disney.

1. Audiences will bail on media networks

Disney's media networks division was once the shining star at Disney. ESPN, ABC, and Disney Channel helped set the tone for the rest of the company. The segment has been in a rut lately, and understandably so. Younger audiences aren't watching traditional TV anymore. Have you seen ABC's ratings lately? Streaming services have binge-hungry audiences unwilling to sit through long ad breaks.

The cord-cutting revolution is real, and that's hurting Disney's cable properties. Cable and satellite television providers pay Disney hefty fees for carriage rights for active subscribers, and that's also trending the wrong way. All of this was happening before Disney+ arrived on the scene, but the service's success is making it easier for fans of its biggest properties to cut the cord. You can now have access to Disney's deep vault of content for a fraction of your monthly cable bill. You can expect to see acceleration in the cord-cutting cadence, and Disney+ will be a big reason for the migration.

2. As the multiplex gently weeps

Movie theater audiences peaked in 2002, and exhibitors have been blaming the growing popularity of streaming services as a culprit for shrinking traffic in recent years. Disney is holding up better than lesser studios. It scored the country's six biggest theatrical releases in an otherwise brutal 2019 for the industry. It doesn't get better from here.

Avengers: Endgame was last year's biggest box office winner. It hit theaters in late April, and less than seven months later it was available on Disney+. Would you pay up to see a movie in a noisy theater when you know you can see it from the comfort of home a few months later, through a service you're already paying for? It wouldn't be a surprise if Disney releases this year feel the pinch as fans realize that they can wait. The tentpole movies will still draw opening weekend audiences, but casual fans and repeat viewings from hardcore devotees will shrink with the success of Disney+.

3. Even the happiest place on Earth might frown

Disney's theme parks won't feel the same pinch as the entertainment behemoth's media networks and studio entertainment divisions, but it may still feel the pain. Disney+ may be a great tool to promote both the history and future of its gated attractions, but it may also scratch the itch for folks planning their next vacations. 

Disney+ could turn Disney fans of the great outdoors into homebodies -- and that's if the next recession doesn't do it first. The argument for Disney+ to take a bite out of Disney's theme parks isn't as obvious as the tug it will have on its broadcasting and theatrical arms, but it's certainly possible. The one thing Disney bulls are feverishly applauding right now could be the very thing that does them in down the line.