Because having a robust portfolio matters, even if you have your strengths in a particular area?
In a perfect world, every publisher would aim to have a lineup of IPs and games across different genres, styles that appeal to the as much of the Venn diagram as possible. It doesn't mean being a jack of all genres, because for example Ubisoft still has a bulk of their resources in third-person adventure open worlds, but Ubisoft lineup are also robust enough to have major titles in genres you don't associate with them like Siege, For Honor, etc.
The important thing is that one would hope Sony doesn't take away resources from their core SP teams or force MP modes onto studios that ain't about that life. But if say, they were taking what they used to budget for Quantic Dream and give it to a studio that can make a good MP game, I wouldn't mind it all that much.
