Supposedly MSGV has like 72% of its total sales from the PS4. There was a thread about its sales distribution from the UK, somewhere around here.
The boost to the PS4 is going to be much bigger from MSGV than it is for the Xbox One, so I doubt they will be that close.
*watch me have to eat my words, a month or so from now when we get numbers, if they actually are less than 40k apart*
Necro-bump this 2020: http://gamrconnect.vgchartz.com/thread.php?id=229249
Bumb in 2021: http://gamrconnect.vgchartz.com/post.php?id=9047071