SP content is incredibly expensive to create. If their goals are to thrive with post-launch monetisation, they would need to massively step up their game with the Battle Pass implementations and purchasable cosmetics. Relying on post-launch SP content is really not advisable. And I would argue that they have made the right decision here, assuming all of these reports are true in some way.
I haven't really worked on a game with paid post-launch SP content nor have spoken in depth with people that have the last few years, but even just a decade ago, it used to be that you would get 10-15% attachment on your post-launch SP content compared to the base game. That is, for the sustainability of the business and how costly the content is to make in terms of money, time and people, not great. It is one of the reasons why companies sell Season Pass packs with or even ahead of the launch of the base game, because selling those when the content comes out, often times months after the release of the game, reduces the attachment rate by a significant amount.
