
Xiaomi maintains a huge product catalogue across the market, however they may be removing their size-focused ranges, likely because size is not a defining factor anymore.
Amongst their huge array of devices and product lines, Xiaomi has maintained their ‘Max' and ‘Note' series as sub-segments of their flagship ‘Mi' brand which both focus on size as a defining trait; the Mi Notes were Xiaomi's most premium offering for years, while the Mi Max's have been their mid-range devices which take scale to the extreme with nearly tablet-sized displays.
Xiaomi has now announced that they will be discontinuing those Mi Note and Mi Max lines though, at least for 2019, as they streamline their segments with the ‘Mi #' line focusing on value flagships, ‘Mi Mix' focusing on “arty” and business use, and their brand new ‘CC' brand focusing on youth.

To be clear, Xiaomi's Lei Jun did not state that the company is abandoning the Note and Max lines, only that they would not see any new releases this year; however the last Mi Note released almost two years ago and I think it unlikely for Xiaomi to release a new Mi Note in 2020 after three years.

The Mi Max seems more likely to return in 2020, given the last only released about a year ago; however I think it no coincidence that the two series that Xiaomi is not updating this year are the two focused on size:
In the world we have today, where the vast majority of phones have huge displays on the order of 6.4″ at stretched 2:1 or 20:9 aspect ratios, there's no real benefit to making phones unusably larger; indeed the OnePlus 7 Pro, which has a comparatively smaller display than a prospective Mi Max would, has been widely criticised for being too large to use comfortably.
And indeed with Xiaomi's primary ‘Mi #' line now sporting a smaller ‘Mi # SE' model, as with the Mi 9 and Mi 9 SE, it could well be thought of as the Mi Note brand just having been absorbed into the main brand.

So, to sum up; Xiaomi has confirmed that their size-focused Mi Note and Mi Max lines will not be returning this year, and based on the trajectory of the industry as well as logistical reasoning and branding choices, I think it a real possibility that we may not see those brands return, at least not in the current market context.
With the likes of the amazing value and large Redmi K20 out there though, I don't think the market is losing much with this announcement.
Source: Lei Jun on Weibo