This is what seemed a little murky, from some of the wording on the current promo pages it can be interpreted that the skins are supposed to last until the end of A-sides event, no specific end date is given. but then the official rules for the season say it’s supposed to be a monthly swap.
The details regarding the Skins for each month of Broadcasts shall be posted to the Promotion website on the Overwatch Contenders Rewards Page.
But do they mean a month from when the broadcasts started? B-Sides event starts on August 12th, which would be a month from when the A-sides began.
It should be cleared up by August 1st. I’m keeping an eye out to see which way it ends up going and adjust if needed. I would recommend if you can get your watch time in now just do it now.