They can't survive on those IP
They don't rely on these IPs to 'survive':
-They sold almost 120M of their console and the newer one would be selling way more if it wasn't for the ship shortages.
-They sold over 1700M games for that console and the newer one according to them has a bigger user engagement.
-They have around 50M subscribers on their game subscriptions.
-They will also be getting a good chunk of money from PC ports of old games, mobile games and movies.
And they have way more IPs than these ones, that's the reason of why MS went to buy Zenimax and Activision.
you can give me big numbers but none of those numbers compare to the wide appeal of Pokémon and Mario Kart.
The PS division make way more money than Nintendo. Because they get that money from more IP and sources.
Playstation as a brand has always relied on 3rd parties
Xbox, PS, all the previous consoles, PC, mobile, VR, arcade... always relied on 3rd parties. Nintendo is the only one who rely on themselves because the major 3rd parties are focused somewhere else.
Call of Duty is huge, and IPs like Warcraft, StarCraft, Diablo, Crash
CoD is huge, but less than 5-10% of the PS users buy them and pretty likely an important chunk of these ones also have an Xbox or gaming PC so won't affect them and will continue with PS, or don't have an Xbox or PC and don't care if they stop getting CoD. If they stop getting it, which may not be the case since according to MS/Acti the said today the same than when the Zenimax acquisition.
Warcraft, Starcraft or Diablo are (or were) big in PC, but nothing on PS. Crash is a former glory, it was big in the PS1, not now.
Part of these sales they may lose will be compensated with the growth PS is having every year, and asigning their budget for marketing deals and exclusives to other top AAA publishers. This acquisition will have a minimal impact on PlayStation.
They could buy the biggest mobile game makers and leave the PC and console race to Microsoft.
Why Sony would leave console to MS when Sony sells 2x the consoles and game subs than MS, and sells more games for console than any other console ever did?
CoD sells 20-30M for each game, so considering around the half of less than that are from PS, not even aprox. 5-10% of the almost 120M PS4 users buy CoD. And PS4 sold 1600-1700M games until they released PS5 (will sell more), and Zenimax being generous didn't sell 50M of them. And part of these sales are thanks to marketing or exclusive deals with Sony, which now will be spend on other companies. And obviously a good chunk of these guys who bought Zenimax and Activision games will continue with PS.
The impact of these acquisitions on PS will be minimal, PS will continue dominating Xbox.
Regarding PC there are a ton of top dogs there, Sony is happy making there some extra bucks selling some millions of units of PC ports of several years old games. They don't care if MS gets stronger on PC. Same goes with mobile, MS will now be one of many top dogs on mobile, which won't affect Sony's mobile games.
Even if Activision continues releasing all their games on PS, if we add the current revenue of MS gaming division and Activision Blizzard is still less than the Sony one.