Yes. When you purchase the monthly lessons in advance, the ‘billing cycle’ remains unaffected; the subscription will auto-renew as usual on the same date every month. The subscription works with permissions. Every month you get a new ‘permission’ which will grant you access to the next level.
Suppose that you are in the 1st month, and your renewal date is every 1st of the month. You will have ‘access level 1.’ Now, let’s say that you buy the lessons in advance on the 28th, then you will have ‘access level 2.’ Two days later, on the 1st, your account will auto-renew, and you will get ‘access level 3.’