The only part of the statement I take issue with is the "50 days to spend a coinbase". Obviously if there's a fork with lower hashrate, the difficulty will adjust down in two weeks. During the two wee...
The two week timer is based on the number of blocks mined. Fail to mine blocks and it is much longer. 2% of hashrate means 50x as long to get to your first difficulty adjustment. Close to 2 years and basically 0 chance of adjusting in 2 weeks unless they change the rules.
Bonus note, hash rate can only adjust 50% in a single period. That means another year to their second adjustment not straight to 10 minute blocks after 2 years. Then 6 months, then 3 months, then 1.5 months.
Follow it out and you are looking at about 4 years to get back to 10 minute blocks at their current signaled hash rate, assuming all of that hash is willing to stick it out losing money all that time.
Bonus note, hash rate can only adjust 50% in a single period. That means another year to their second adjustment not straight to 10 minute blocks after 2 years. Then 6 months, then 3 months, then 1.5 months.
Follow it out and you are looking at about 4 years to get back to 10 minute blocks at their current signaled hash rate, assuming all of that hash is willing to stick it out losing money all that time.
