There are 3 issues that I have heard about EV's from skeptics and just people in general.

1. Range
2. Weight
3. Saftey pertaining to fires

1 is being addressed drastically across the field 2 is as well if you look at any off the solid state batteries. For instance Honda is basing their advancements on using high density but creating smaller batteries, as they believe 1000 miles is going to be easily attainable but unnecessary for many users. So launching a vehicle with a 500 mile range that can charge faster and carry less weight is something they want in their repertoire. I would argue both 3 & 2 are being addressed in this setup IF what they are saying is true. It can cut back on fires, which scares buyers and gives ICE owners strawmen to pick at and try to make into a much larger issue than it really has been (at least in the U.S.). As for 2, it allows for a sturdy building block that attached to the frame, thereby cutting down on beams needing to be installed to brace the battery in place that already weighs more. IF they can keep the battery at the same weight, and not need the extra support beams, then you cut some of the extra weight. Throw in Hondas smaller batteries and all the sudden you have EV's going 500 miles, at the same weight of an ICE vehicle for the same price. Maintenance costs lower, impact on the environment drastically lower at that point, and charging an EV off your home electricity costs in most of America would be 1/3 of buying gas.

Edit to throw in, we don't have to ship oil tankers across the oceans constantly, cutting shipping impacts. (Some estimates show coal and oil shipments being up to 40% of our shipping overseas).

Other obvious factors than density are: Price, weight, durability and safety.
These excel ar price durability and safety. Which is also mentioned in the article.

what the game changer is

Simply put: Nobody else is using LiFePo (or LFP) batteries in electric cars so far.