Sony games were selling more than the MS ones before the Zenimax deal. If Zenimax games sold around 50M on PS4 being generous, they weren't even a 3% of the over 1700 million games sold for PS4 a few years ago (plus more games that will be sold until it dies, so very likely will end being a way smaller percent).
So the Zenimax deal was going to have a little impact on PS, specially considering that part of these sales were due to featurings and exclusivity or marketing deals with Sony, that Sony now will make with other publisher as they could do with the spare games from Activision that Sony supported, as recent Crash or Tony Hawk. The Blizzard games are mostly PC stuff that didn't affect PlayStation.
PS4 sold almost 120M consoles. Every CoD game sells around 20-30M copies, and a good chunk on PS, let's say around 10M. So less than 10% of the PS4 users buy CoD. And in case CoD leaves PS (something very likely) we should see which % of them would leave PS because of that.
Part of these sales were also thanks to marketing partnerships with Sony, that one will be assigned to other companies, so part of these sales will be compensated with this. And PS has been growing during years, so this growth will compensate the remaining.
So the impact on PS hardware and software sales won't be that important, they will barely notice it. PS will continue selling the double of the amount of consoles than Xbox does, and will continue selling a shit ton of games more for it than Xbox does. Sony's gaming division makes more revenue than the Xbox gaming division+AB, and this is counting that now AB gets a ton of revenue from PS which pretty likely won't be there in the future.