Once a representative from LEGO files a VeRO (Verified Rights Owner) files a claim against the sellers involved, the listings in question will be taken down. If, as you suggest, there’s lots of these listings out there, it may take them a while.
You can possibly help bring the listings to LEGO’s attention by reporting the listings yourself, but don’t expect eBay to take action based solely on your say-so. LEGO is considered the expert on their products, so the claim has to come from them.
This is an older thread from the US boards from the perspective of a seller caught in the net, but you might find the general information useful despite its age and perspective:
https://community.ebay.com/t5/Selling/VeRO-Claim-from-LEGO-on-OYO-Sports-Products/td-p/31771908
