In terms of numbers:
Chances of getting full hero from Bronzium are between 2-4% according to different data. Let's take the best ones, i.e. 4%. There are 33 heroes available from Bronzium Data Cards, so 4/33=0.12% chance to get Poggle from a single Data Card. You get 5 free data cards every day and up to 1000 ally points in ordinary battles, challenges and daily reward, i.e. every day you have something near 1.1% (0.12*9) to open Poggle. For the worst chances it will be twice lower (0.55%).
As a lawyer, I'm not sure in accuracy of my calculation (I don't feel like maths is my element), but it seems to be something like that. So, if true, may be there is a good reason not to hurry with activation.