Xiaomi will cease official software support for the Mi Max and Mi Max Prime in April
The Mi Max and Mi Max Prime may have foreshadowed the 6-inch-plus-screen trend back in 2016. These Xiaomi phones share the same 6.44-inch full-HD screen (albeit with a relatively massive chassis due to the lack of notch back then). However, the Mi Max Prime was graced with the Qualcomm Snapdragon 652 chipset, whereas the plain Mi Max made do with the slightly less powerful Snapdragon 650.
These extra-large 2016 phones received regular updates from their OEM, as it had stable and beta upgrade programs for the two first-generation Mi Maxes. Xiaomi has recently announced that those users in the latter update stream has received its last OS download. It was a MIUI 10.3 build, which is based on Android 9.0 (Pie) and made it up to version 9.2.28 for users in its beta program.
Therefore, development for the Mi Max and Mi Max Prime has effectively ended as of March 1, 2019 (the date on which the final beta was released). Xiaomi has also stated that these phones will also receive a final stable build, based on the 9.2.28 beta, in April 2019. However, it can be argued that the original Mi Max series has had a good run. Furthermore, its upcoming successors, the Mi Max 4 and 4 Pro, is rumored to have an even bigger 7.2 inch screen with a teardrop notch and the up-to-date Snapdragon 660 or 675 SoCs.