Analyst Ming-Chi Kuo has pretty knowledgeable sources deep within Apple's supply chain, and has a good track record with respect to identifying features and specs for upcoming hardware. Given that the 2019 iPhones are just a few months away, we already have a good idea about what they will look like, and what features they will have, Kuo is focusing his attention to next year.
According to Kuo, there will be three distinct iPhones models released in 2020, and for those that prefer a smaller device, there's good news in store. The flagship models will be available in either a 5.4-inch or 6.7-inch OLED configuration. This is shift from the current iPhone XS and iPhone XS Max, which have displays measuring 5.8 inches and 6.5 inches respectively. The smaller 5.4-inch entry might not bring the iPhone family down to the positively "dainty" size of the iPhone SE, but it's a step in the right direction for people that have grown tired of smartphones growing larger with each generation.
With Apple's [small] premium flagship moving down in size, that leaves more breathing room for the entry-level iPhone, which will retain its 6.1-inch display size. However, according to Kuo, it will shift from LCD technology found on the iPhone XR (and still expected to stick around for its 2019 counterpart) in favor of OLED.
Although the 6.1-inch iPhone will gain OLED technology, it will miss out on one critical feature. Kuo reports that this model will retain 4G LTE connectivity, while the premium 5.4-inch and 6.7-inch iPhones will come with 5G modems. And considering Apple's recent agreement with Qualcomm, you can expect to find Snapdragon X55-class modem paired with the Apple A14 SoC. These 5G models will reportedly support both mmWave and sub-6GHz wireless bands giving iPhone users the best of both worlds with respect to speed and coverage.
In addition to 5G connectivity, other rumored features on tap for the 2020 iPhones include an acoustic fingerprint sensor in the display, which would function as a sort of new age Touch ID.
Of course, all of this information is pure speculation, but given that it's coming from Ming-Chi Kuo, we'll refrain from throwing on a heavy dose of salt.