Honestly I don't know which user would prefer to pay weekly and to lose the most useful features of the app like email import and calendar sync.
You could have left the montly plan with the whole features together with the weekly one...just say that you have found that the yearly is more remunerative in the long term, and that you just wanted to force the monthly subscribers into buying the yearly plan to have the "real pro", since no one sane of mind would pay for that useless plan.
Also for people like me who have the necessity to switch between countries due to app restrictions it's really unfeasible, since we would lose access to the plan and have to pay a whole year again at each change.

Will stay with App in the air...I wanted to migrate all my records and use Flighty, but it's impossible to do it without the full calendar import feature of the pro.
Gosh...at least let people import the past history without having them to pay for a year long plan that they might not use.

Sad to see that greed wins over rationale...evidently easy money is worth losing potential customers in favour of pennies.