The current generation of conventional consoles continues to have its lead over the previous one eroded. But as before this is the result of a post-peak XBO having its worst year so far going up against the 360's 2011, that system's best year, causing the XBO to rack up a rapidly-growing deficit against its predecessor. Meanwhile, the PS4's 2019 is running against the PS3's 2012, a much more favorable match-up, one where the PS4 still manages to maintain a lead of over 8M units, a lead that it will likely grow some in November.
Also, the PS4 is right on the verge of 30M. Due to uncertainties in the data for the past three months it's unclear if it has passed that mark or not (the numbers I have put it at only 2700 units away), but if it hadn't already passed it by the end of August it most definitely did once September ended.