I would think that any team finishing within the top 3 after the H&A season is a genuine flag threat, unless there's a supremely dominant H&A team that's finishing on top with 19+ wins. Geelong have ended the H&A season in the top 3 in 2013, 2014, 2016 and 2017, and in two of those seasons (2014, 2016, 2017) only percentage stopped them from being the minor premier, and in the other (2013) they were one game behind the minor premier.
You can say that they might not have appeared as strong or dominant as they did between 2007-2011, but in the context of each given year, they were/are very much genuine flag threats going into finals in each of those top 3 years I mentioned.
The only years since 2007-2011 where they've looked genuinely behind the top teams were 2012 (finished 6th, out in the first week of the finals) and 2015 (finished 10th).