T-Mobile will be increasing its threshold for deprioritizing unlimited customers who use large amounts of data, and that threshold may go up as high as 50GB, according to a report from TMoNews. News of the change comes from an anonymous source, which said that the company will be bumping the limit up on September 20. When asked about the leak on Twitter, T-Mobile did not confirm what the new limit would be, but did say that the deprioritization threshold would be increasing, and that the change would indeed be taking place on September 20. While a leak is still a leak and should be scrutinized as such, especially from an anonymous source, T-Mobile's confirmation of the date adds a bit of credence to the leaked limit.
T-Mobile's threshold for deprioritization long sat near the 20GB mark, fluctuating once in a while. While competitors have stayed in that area, T-Mobile recently upped the limit to allow a single line to accrue 32GB of data usage before deprioritization would take place. The new 50GB data cap, if the leak is true, would add 18GB to the current amount, and almost triple the original limit from back when T-Mobile first began offering its T-Mobile ONE plans. While older unlimited data plans on T-Mobile were, for the most part, truly unlimited for a little while, the company has since brought the same changes that newer subscribers are getting to grandfathered plans. This means that those who have had the same plan since before unlimited data plans were taken off the menu will likely have the new 50GB cap in place.
As a refresher, deprioritization is not the same as throttling. Whereas throttling will set your data speeds to a fixed limit, deprioritization will cause your LTE connection to be tagged as a lower priority than other users in your area. In other words, if there are few users on the same tower as you or they're all using relatively little data, your speeds won't be impacted much, if at all. Once there are a large number of users on a single tower using up large amounts of data, however, your speeds could slow to a crawl. Deprioritization puts you at the bottom of the heap, in terms of data speeds among a set of users on a tower. Nobody will have more connection lag or slower speeds than you, aside from other users who have hit the threshold and been deprioritized.