I am all for keeping everything on PC only for the time being because otherwise I have to split into two tournament prizes (One of PS4, one for PC) if we segregate them.
I think most folks have the PC version anyway - a lot of people got the PS4 version for free when it was a PS Plus game.
When you PM me or post here intending to join, please post or send me in a PM your Steam handle so I can add you. If we are low on folks, I can open it up for PS4 but true cross play would be in effect as I don't want to segregate it.