The cap's probably less about protecting your wallet right now and more about future-proofing before Chinese manufacturers actually build real distribution networks. BYD and others have been ramping up European presence gradually - you're starting to see them in some markets, just not everywhere yet. The 350,000 limit mostly locks in the status quo rather than stopping some price collapse that was coming.
Where this gets interesting for buyers is the long game. If Chinese brands had continued growing their footprint without restrictions, they'd eventually compete directly with mainstream European and Japanese models on price. Right now when you walk into a dealership, you're picking from familiar names. That cap means those household brands don't face as much downward pressure on pricing from new competitors in maybe 3-5 years. So in theory, your local options stay less crowded, but also less price-competitive. You won't notice it as a dramatic shock because the Chinese brands aren't household names yet - it's more like a brake on disruption that might've happened.
The real impact depends on whether European manufacturers themselves start making cheaper hybrids to compete. If they don't, then consumers in the EU potentially miss out on whatever value proposition BYD or similar companies could've offered. For now though, go shopping and you'll see the same players you've always seen.