im not too familiar with other franchised esports, but are there any other games where T2 teams have a chance of being promoted to the Franchised leagues?
Dota 2 has a pretty good system although it is not necessarily a franchised format.
there are 16 teams divided into 2. Div 1(tier 1 teams) and Div 2(tier 2 teams). there are 3 splits, after each split the bottom 2 of div 1 and the top 2 of div 2 are swapped. the bottom 2 of div 2 will have to go through open qualifiers again.
Also, when The International(Basically Champions but for Dota) comes around all the div 1 and div 2(except the bottom 2 of div2) teams will go through LCQ if they didn't qualify by points. so even if you are in Div 2 you can still qualify for The International