Reality is always very murky. We don’t always tag things exactly as they should. For example a village of 300 people might be a town officially but we would tag it as a village. So I don’t believe the exact trunk tagging need to apply to the exact length of the motorway and it could also be slightly extended to better facilitate navigation for the router. The first changeset you listed showed a disconnection between the two trunk roads, I think that little piece should be tagged as trunk as well even though it’s not part of the motorway.
Disclaimer: I know next to nothing about motorways.