Luckily, the EU included substantial anti-circumvention provisions in the DMA. I'm not a lawyer, but based on the excerpts from the regulations below, it seems likely the EU would have grounds to open legal proceedings against Apple's new rules.
https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELE...
"Article 13: Anti-circumvention
4. The gatekeeper shall not engage in any behaviour that undermines effective compliance with the obligations of
Articles 5, 6 and 7 regardless of whether that behaviour is of a contractual, commercial or technical nature, or of any other
nature, or consists in the use of behavioural techniques or interface design.
7. Where the gatekeeper circumvents or attempts to circumvent any of the obligations in Article 5, 6, or 7 in a manner
described in paragraphs 4, 5 and 6 of this Article, the Commission may open proceedings pursuant to Article 20 and adopt
an implementing act referred to in Article 8(2) in order to specify the measures that the gatekeeper is to implement."
https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELE...
"Article 13: Anti-circumvention
4. The gatekeeper shall not engage in any behaviour that undermines effective compliance with the obligations of Articles 5, 6 and 7 regardless of whether that behaviour is of a contractual, commercial or technical nature, or of any other nature, or consists in the use of behavioural techniques or interface design.
7. Where the gatekeeper circumvents or attempts to circumvent any of the obligations in Article 5, 6, or 7 in a manner described in paragraphs 4, 5 and 6 of this Article, the Commission may open proceedings pursuant to Article 20 and adopt an implementing act referred to in Article 8(2) in order to specify the measures that the gatekeeper is to implement."