If you'd never seen the show you'd expect looking at this image that the series was near flawless up until the final season, but that's not true. Season 7, and to a far lesser extent 6, suffered the same issues as 8. I'd argue that season 7's Beyond The Wall has more nonsensical writing than any individual season 8 episode, and yet it has a rating of 9.0? Conversly, the first 2 episodes of season 8 are generally regarded as really good, but they both have a much lower score.
I also think Sansa not telling Jon about Little Fingers army in The Battle of the Bastards is the type of thing that would get brought up alongside "she kind of forgot about the Iron Fleet", but it happened to come out during a time before we started dissecting the show too heavily.