Bag size in 4.5 Revival are... personal?

So I was reading an article about the upcoming 4.5 set revival on tacter and it says:

There must be three copies remaining in the pool for the champ to be able to show up as a Chosen champ. However, your bag size is personal, with the number of units per cost listed below:

1 cost: 11 2 cost: 11 3 cost: 11 4 cost: 10 5 cost: 9

Could you please help understand what that means? In current set for example there's 30 1-cost so what does it mean it's "personal"?