I mean you are right to eschew discord but this isn't really particular to discord. Scraping messages for something like this can be done on any public chat room regardless of which boxes you may have that it ticks; it it's floss, decentralized, nationalized, communist, on the blockchain, indie, community run, simple protocols, whatever, in the end if anyone can read it then someone can scrape it. Discord was targeted because it was popular that is all.

Unless you eschew discord because it's popular and not because it sucks in which case score one for the hipsters I guess.