The EU is preventing price discrimination within the EU.
They do have that requirement as part of the Digital Markets Act, but I don't believe that that's what the case here is addressing. That is not what the article OP posted or the article I linked to is saying: they are specifically saying that what is at issue is sales outside Europe.
EDIT: I am thinking that maybe the article is just in error. I mean, just from an economic standpoint, the EU doing this would create a major mess for international companies.
EDIT2: Okay, here's an archive.ph link of the original Bloomberg article: