There's no reason for them to keep defying the court. It could make the ruling worse for them and GDPR fines are hefty to begin with. They can't possibly hope to gain anything of equivalent or greater value to the fine from a bit more data.
They will do it regardless and just pretend they didn't. GDPR would already protect you if you're from the EU, but as you can see, they don't really care about that.
Legally? No idea. What might be adequate protection in the country your instance is hosted, is probably unenforceable in another country where a federated instance might be.
Technically, you could try by using your own, self hosted instance, and not federating with others, so they won't be able to scrape your content as easily.
But realistically speaking, your comments are possibly more likely to be scraped on Lemmy, since it's so much more open for bots, and your content is replicated to much more servers, not all of which may have noble intents.
That's true as well that I hadn't thought of, one could just spin up a VPS in a country that doesn't give a shit about licensing agreements and use a bot to scrape the data, or even just spin a instance up and Federate/subscribe with everyone that is an open instance / doesn't use the whitelist (i.e most of the instances) and scrape that way. The only real defense against the latter is defederation, but that system isn't very advanced and is easily bypassable if you don't have a bunch of users
Personally I would be absolutely shocked if this wasn't already happening, downside of a free/decentralized protocol I guess
I don't think you can, some have a license notice at the end of each comment but I have major doubts that it would actually hold up in any actual court hearing