What the 2 day blackout does is it nudges people to explore alternatives. With this, Reddit management has lowered the barriers to exit. When the next boycott comes, migration for many subreddits will be easier.
Which will be when all the third party apps stops working and people realize what hot garbage the official app is.
I don't think 2 days is significant enough for that slash I don't think an alternative to reddit exists given the fact that it has millions of users and millions of different niche subreddits