> or, if the source code is not publicly released, after an update of the same operating system is released by the operating system provider
They have not released the source code, but they have released an update of their operating system on their reference Pixel hardware.
Therefore, all devices must update within 4 months of that Pixel release, regardless of source drops, per this law
I would also argue a closed source release in August 2025 would start the first 6 month timer (February 2026) and the source code release to trigger another timer (if they differed in any way between the closed source release).
A lot of this law is abstract and only if the EU challenges Google's approach would it be decided how it's meant to be applied in reality.
Your comment seemed to imply that a source release would trigger a different timer than a binary release, which is explicitly covered as the same thing in the law - for both the 4 and 6 month timers.