When it comes to purging it really depends on everyone's skin as everyone's skin is different. I have experienced purging and when I went to a dermatologist she didn't even know the term purging as she didn't believe it exists. Every time I tried a new routine where a new type of medicine was involved my skin would Purge. When your skin is used to a certain type of medicine like salicylic acid or benzoyl peroxide it does become dependent on it so you don't Purge but if you do stop using it your skin would become worse. My skin purged when I tried tea tree oil for about a week. Just stick with it. With anything it has to get worse before it gets better. My skin is purging now because i tried a different moisturizer

I have a few pimples popped out here and therein the beginning of 2% Salicylic Acid usage.
Afterthe usageforroughlya week later,new pimples didn't occur THAT much currently on my face, it still does, but lower amount that it used to be, but I'm unsure ifthe pimple forming isactually due to Salicylic Acid purging or the other ingredients that comes with it that trigger the breakout.

I don't know if acne purging is scientifically proven or not either, would be appreciate if someone could enlighten me regarding this with sourced information..

Peels, resurfacers, basically AHA/BHA products will make you purge. Some medications or supplements will make your skin purge, like Accutane, high doses of vitamin A, or lysine. Most products, lik moisturizers do not make you purge, they just clog your pores or they don't.
Purging time can vary...It can be prolonged if you are still using other products (or dietary triggers) that continue to cause clogs. Generally speaking, weeks 2 and 3 tend to be the worst, with significant improvement coming in 4 weeks and beyond. It takes roughly 28 days for your dermal layer to completely turn over, so this makes sense to me.