Exactly.
The gaming industry is around $200 billion. And Activision's annual income statements show they do about $8 billion sales. Out of that $8 billion only some of it is Sony based as they got multiplat games, WOW, King etc.... Out of all of Sony's gaming division sales, that Activision portion is going to be a small part of it.
Despite Activision being the biggest third party company, they are actually still just a tiny part of the gaming ecosystem.
MS's Minecraft and Bethesda games have shown zero "cutting the cord" too against PS or Nintendo gamers. So even if people get nervous at the deal, full support is still there.
Now whether full support comes later who knows.