No chance. Hara knows he can't end the series with the Gyou or Coalition War Arc being the ultimate arc overall, and there's still a lot of content ahead. I won't go into History spoilers but the year of 236 BC ended in about 647/648 iirc, there has been about 52 chapters since then and assuming starting on Chapter 701 we enter the Year of 233 BC, then Hara has 52 chapters per two years to keep up the consistency now. The story should end at 206 BC, which gives 27 years in story time left. Hara on this pace would still write & draw about 702 chapters, meaning we're still halfway in the story in a sense.
Is that reliable? No lol. The Chu Arc is very big on Shin's character, the same way as Gyou and the Coalition Invasion were, if not bigger, and there's many other pieces that will happen in that arc other from Shin, so that's already another 100+ chapter arc. The politics of Sei are far from over as well, so we'll still get an arc or two with him as the central focus again. Kyoukai, Ouhon, Mouten, etc. peaks have yet to be reached historically. We still got antagonists like Riboku, Shibashou & Prince Ka in Zhao, Gohoumei's faction in Wei, and the entire states of Chu, Yan, Han, & Qi. The rise and fall of Sei has to be heavily adapted, which leads into the Chu-Han contention which is clear that Shin might preform an Ouki with a young Han Xin or Liu Bang.
Lots and lots and lots of content to be covered, this is why I pretty much say that Kokuyou Hills, Gyou, and Eikyuu are pretty much the Thriller Bark, Saobody, & Marineford trio of Kingdom, as no matter how you look at it, we're halfway through the story in both history and content. Enjoy the next 15 years my brothers.