Nah, over the years I have seen many discussions sites rise and fall, and you tend to get over it. Slashdot, Fark, Digg, and countless PHP-based boards for instance. I am happy that there is a real possibility that a decentralized mechanism for discussions is catching on again. To me it's somewhat like Usenet back in the day, but prettier.
I think the old (and new) Slashdot-minded people will continue on Lemmy from now on, while most of the others who are not interested in tech topics will go back to Reddit once the blackout is over.