Lemmy and other federated solutions will get a big boost in users, but it will only very be a tiny fraction of the reddit userbase.
And 98% of those users will probably just head back to reddit in a week or two.
Subreddits that have closed and moved with be replaced with new subs on reddit.
I think in the end it will be a healthy boost for Lemmy, but so far I suspect don't think we are at "Mass Paradigm shift" yet.
This is not going to be Digg > Reddit
I am a shitty programmer, and I would never want most of what I do to go anywhere near Main.
But as you said, I have a few things that I run as forks, with my own little tweaks.