You can see in the second (dusk) rendering that they actually left space for the Grand Park towers but didn’t add them in, which is not unusual for tower renderings.
What I’m guessing happened is that they were rushing to get these renderings out and multiple people made a mistake. They likely forgot that the towers were there (since so many promo materials leave them off anyway), realized something wasn’t adding up, and just extended the podiums to fill the extra space. You can see that there is a significant difference in the length of the M6/M7/M8 podiums between the two renderings.
What perplexes me, however, is how someone would have missed this, given that they would have had to remove the Grand Park towers from the image in the first place.