Thank you for providing this additional information and perspective. It aids my understanding.
I however (as you might imagine) would argue that the ongoing link between Medium and Twitter is wrong at its core and should end. I am also sensitive to the issue of Medium members having hard won communities on Twitter and to the issue of unilaterality. But Medium could explain to all member that, in an ongoing effort to withdraw support for a deeply flawed social media platform, it is ending ALL involvement with Twitter, and provide a reasonable time frame for that change. Affected members could then adjust just as we've adjusted to other changes Medium has decided to make over the years. Additionally, Medium is not linked to ALL social media platforms, just three presently. Linking with another, more socially responsible platform, would certainly be possible and perhaps welcome.
Again, thank you for your willingness to engage in this dialogue.