> it's arguable that the DSA (Digital Services Act), which is just as applicable, actually compels Apple to de-platform this app
I'll assume this is completely bogus, unless you elaborate.
Also, the text of the DMA confirms that they can only restrict apps outside of the App Store if they endanger the integrity of the OS, not for any other reason. Not even for "enabling IP infringement" (which browsers would also be guilty of).
The EU does seem to take violations of the DMA seriously, and this is unambiguously a violation.