Merge pull request #285 from TwoSpikes/main

OnePlus: add information about ColorOS 17

Author: Lost-Entrepreneur439

brands/oneplus/README.md

@@ -15,6 +15,20 @@ According to the [OnePlus forum](https://bbs.oneplus.com/thread/1926504022886318
 
 > **Note:** These restrictions currently apply only to devices sold in mainland China. However, due to the unified OPPO–OnePlus codebase, similar restrictions may be introduced for global models in the future.
 
+Note that starting September, 2026, OnePlus will make "Deep Testing" program much harder (even on coloros16, not just coloros17+) ([link to OnePlus forum](https://bbs.oneplus.com/thread/2175833961601695750)). Note that this only applies to Chinese versions of OnePlus smartphones. It now requires:
+- your real name
+- face verification
+- 7-day account login requirement
+- 7-day approval process
+- 14-day unlock window
+- Limited monthly unlock slots
+
+Even though OxygenOS 17 is officially cancelled (every version of OnePlus 16 will be initially released with ColorOS 17), "Deep Testing" program will be needed only on Chinese versions.
+
+Note that if you updated your OnePlus 11-15 to ColorOS 17 (when it will be released), you will be able to downgrade it to OxygenOS 16 through official Rollback package (note that it is not released yet). Note that it works even if the bootloader is not unlocked. Note that it works only on global versions of OnePlus. Note that after downgrading, you will not be able to flash any custom ROM based on android 16 other than that Rollback package, because this package has patched ARB index.
+
+> **Note:** This information may not be correct because ColorOS 17 and OnePlus 16 are not released yet
+
 ## T-Mobile
 For OnePlus devices purchased from T-Mobile or an MVNO such as Metro, even if the device was later unlocked from T-Mobile, they require an [unlock token], and to get your unlock token, you need to provide original proof of purchase from T-Mobile. If you purchased the device from eBay, you will not be able to unlock your bootloader. This does not apply to the OnePlus 6 or earlier. This doesn't appear to apply to other third party sellers (such as OLX).