There's too much in the Apple rumor pipeline to squeeze into the rumored March 25 event.
From Juli Clover's MacRumors' Upcoming Apple Products Guide:
This year, Apple is planning to host an event on March 25, but it's going to be focused on subscription services and therefore may not include hardware announcements. Instead, these updates could potentially be announced via press release right around the time of the event
- iPad mini 5 - Same design as iPad mini 4 with 7.9-inch display and 6.1mm thickness, but with an upgraded processor, lower price tag, and possible Apple Pencil support. Headphone jack and Touch ID expected.
- 7th-generation iPad - Same design as 6th-generation iPad, but with an upgraded processor and a new 10.2-inch display size. Apple Pencil support, Touch ID, headphone jack, and other iPad features to remain.
- 7th-generation iPod touch - Little is known, but same design as 6th-generation iPod touch with no Face ID or Touch ID. iPhone-style bells and whistles not expected, as Apple will likely want to keep costs low, but it will have faster A-series processor.
- AirPods 2 - Wireless charging case expected, as is "Hey Siri" support. Rumors have suggested some slight design changes including a matte coating for better grip, a new black color option, and health-related features as possibilities. Info is mixed, though, and at least one rumor suggests a Charging Case is coming while new AirPods won't be launched until fall. Apple analyst Ming-Chi Kuo says to expect new AirPods with a wireless charging case and upgraded Bluetooth in the first half of 2019.
- AirPower - Apple's long-delayed wireless charging mat for AirPods, iPhone, and Apple Watch is finally in production and is expected to launch in the first half of 2019.
- Apple News Service - Apple is planning a $9.99 per month subscription news service that would give unlimited access to paywalled sites like The New York Times and the Washington Post. Not all news sites are on board yet, but this is expected to be announced at the March 25 event.
- Apple News Magazine Service - There have also been rumors of a $9.99 per month service that would give access to magazines, similar to the service offered by Texture, the magazine app Apple bought in 2018. Whether magazines will be included in the same $9.99 fee for news or available separately remains to be seen, but expect to see both news and magazine subscription services added to Apple News.
- Streaming TV Service - Apple is working on a streaming TV service that will include the more than two dozen TV shows and movies it has in the works along with access to subscription content from other cable providers. We don't know what it'll cost just yet, but Apple will debut it at the March event before launching it later in the year, perhaps in summer. By the way, all of Apple's services may be available in one big bundle option, so the TV service could be paired with the news service and perhaps Apple Music.
- iOS 12.2 - iOS 12.2 expands Apple News to Canada, brings HomeKit and AirPlay 2 support for third-party TVs, and adds a few other new features to iOS, and we're expecting it to be launched on or before Apple's planned March 25 event.
My take: I consider MacRumors the official Apple rumor source. The current Product Guide also has entries for June, September, Later in 2019, Coming in 2020 and Beyond 2020 (One entry: Apple Car).