This is 100% speculation made by myself based on launches in the next few days and current phones available in other regions.
MediaTek has officially announced that the Dimensity 800 will be coming to Europe with a launch planned this week.
When I pressed my PR contact further, I was given the official statement from MediaTek:
MediaTek works with many of the major smartphone brands, some of which are growing their presence in Europe. We can't confirm exact timeframes and partners at this stage, but you can expect to see announcements in the coming days and weeks.
I would have bet that this would have been Realme or Xiaomi. However, neither of these companies have a phone with the MediaTek Dimensity 800 yet, and the Realme launch isn't until next week.
The two launches this week are the Xiaomi Mi 10T series and the Oppo Reno4 series.
Today's Xiaomi Mi 10T series launch probably won't have a Dimensity phone
Today, Xiaomi will be announcing the Mi 10T series, so if they are going to announce a MediaTek Dimensity 800 based phone, it is today.
However they don't have a MediaTek Dimensity 800 based phone, instead, the Redmi 10X uses the Dimensity 820 5G.
Xiaomi has previously teased a new affordable Mi 10 5G phone using the Qualcomm Snapdragon 750G, so it seems unlikely they will launch a phone with the Dimensity 800 today.
OPPO Reno4 Series UK launch to include Reno4 Z 5G (A92s) – Probably under a different name again
OPPO have already launched their Reno4 Series in other markets and the Oppo Reno4 Z 5G was announced on the 28th of September in Taiwan. This phone is a rebranded Oppo A92s and one of the few phones on the market to be equipped with the MediaTek Dimensity 800.
The phone has a 6.57-inch 1080×2400 20:9 LCD touchscreen with 120 Hz refresh rate, a quad rear camera setup (48 MP main + 8 MP ultrawide + 2 MP macro + 2 MP depth sensor), dual selfie cameras in the elongated hole-punch cutout in the screen (16 MP main, 2 MP depth sensor), and a 4,000 mAh battery with support for 18W charging.
The Oppo Reno4 Z 5G runs Android 10 with ColorOS 7.1 on top and will be offered in black and white, and should make it to many other markets soon.
I would bet good money they will ditch the Z branding for the UK/EU launch.
Realme 7 Series Launch may have a surprise Dimensity 800 with a 125W UltraDart charger
In more recent news, Madhav Sheth, the CEO of Realme India and Europe, teased that a new phone will be launching in Europe with a 125W UltraDart charger soon, with the hashtag #FAS7ER
The Realme 7 series launch is next week, at the moment the only Realme 7 phones announced in other regions are the 7, 7Pro and 7i.
I am not aware of them launching anything else next week, one possibility is that they could tease a new phone and hold yet another launch sometime in the near future. Either that or they may surprise us all with a brand new unannounced phone.
Currently, Realme has the X7 wh which is very similar to the Realme 7 Pro but with a MediaTek Dimensity 800U 5G instead of SD720G. The Realme X7 has a 65W charger, so it could be a tweaked version of this gets launched with the Dimensity 800 and 125W charger.