Only 36 packs... If it's 12 weeks until the next set, then that would be equivalent with the current system. If it's at least 13 weeks until the next set, that's fewer packs than the 3-a-week would have resulted in.
edited: 3-packs a week = 156 total per year. Whereas assuming they continue with the mastery system for each set, at 36 packs per set, that's 144 pack per year.
edited part 2: If they vary the number of free packs to match weeks between sets then it could end up being equivalent with the current system. And given they keep tinkering with the reward systems, it could very well have changed by this time next year.
The number of packs available will shift with the duration of sets. It’s one of our goals to not reduce F2P earn with this system; we’ll adjust as needed to make sure we hit that.