when is labor required of FOSS? I always assumed that I was perfectly free to not write FOSS but I'd be interested to find out in what manner I can be compelled to do so. Keep in mind that asking, even asking forcefully or impolitely, is not compulsion. Compulsion is about what happens if the request is not fulfilled.
Even now, the CRA is very vague -- any commercial activity tenuously related to a piece of software you share can force you to do work for the EU. Of at least try, if you don't tell the EU to shove it. And that commercial activity doesn't even need to be in the EU.
Had they followed through with that, it would be compulsion and the comparison to slavery would have been warranted. And the devs did exactly what I would have and what they should do, which is to withdraw any software they're not willing to support. To my mind this process is exactly what the OP was talking about: devs offer software for free with no support because that's what they're willing to do for free, someone demands more free labor from them under the guise of accountability, devs say "I'm not willing to do that and if that makes distributing this software illegal that's fine, we'll pull it down", lawmakers back down and move on to gazing in the mouths of other gift horses.