Mark....what Ms Wente says in her article is essentially reproduced in the link I've provided here. The experts noted in that CBC article do have actual science backgrounds. 

in essence...Monarch population is recovering...it is not where it used to be 20 years ago but it's up dramatically from it's bottom in 2013...milkweed plantation is occurring  as a means to support population growth etc etc.....so, we still have a problem, but we may be on track to solving it with continued vigilance and effort.