I've spoken with the developer John Torode quite a bit on this project, they are staying with the branding of calling it 'arriVa 42'. However the 43 floors instead of the 44 shouldn't affect the height as it may just be a floor count issue, they are now including 2 story loft units on the podium section. So they may just be counted as 1 floor in the stories count, not the actual construction count.
Keep in mind this is similar to the first tower arriVa 34, which is actually 36 stories in total. But has only 34 stories of residential units, it lacks a 3rd and 13th floor in the listing on the elevators.
I'll supply more photos of this one coming up from my vantage in the first tower as construction continues!