I wouldn't be surprised if it's full of shortcuts with privilege escalations or contradicting exceptions.
Not because it's Huawei, but because it's a single company developing BOTH the Operating System and the hardware it is supposed to be deployed in.
When it comes to meeting a production deadline of a product, the pressure to apply a quick workaround is much much higher than the pressure to follow a structured process from whatever platform-team.
Source: I worked in lots of companies which at some point tried to establish various kinds of frameworks, just to be forced to break them again in order to ship on-time...
That's what Apple has been doing for nearly 20 years now.
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If you expect that Huawei will:
delay a million-device mass-production for i.e. China Mobile because the project-team needs to wait for the platform-division to implement a fix in their common core and complete the entire release-process, for the project-team to then merge their code again on-top of this new release and start retesting the impact of all the other patches,
-> instead of:
the project-team just patching their fork of the platform, release a new build for China Mobile immediately and take a note to "deal with this later"
then you have not seen the reality of this industry yet.
Even Huawei's existing products are a multitude of forked and re-forked codebases with changes left and right, updated/outdated libraries and ever-pending merge-tasks. I don't expect this to suddenly change now