[tgtweak]

And, do they need to do it or are they just data mining?

[t0astbread]

If they don't need it, isn't it illegal to collect that data under the GDPR?

[TeMPOraL]

I don't see the repo actually saying they're collecting this data, i.e. sending it back to their servers. It may just be a "reverse adblocker" - a list of signatures of extensions that the website's JS will try to interfere with on the user end.