I guess I could see it either way, but the fact that the date was an important detail that had to be "earned" made me feel like the way it recontextualized that cutscene was the point.

I could also see it as a, "we confused people too much with that Didact monologue at the end of Halo 4, so let's put a date on this one so people won't be confused" and it backfiring and causing the same confusion. :P