There was no reason to use it before. It was simply terrible at getting damage on target at all.

Now, it is far superior and the most spammable shell type for MBTs.

Quoted from "NoctyrneSAGA"

There was no reason to use it before. It was simply terrible at getting damage on target at all.

Now, it is far superior and the most spammable shell type for MBTs.

Can the HE shell fit in a more AT-orientated loadout?

Because it is now meant for anti-infantry, which is why it is terrible to shoot tanks with now. Think back to WW2 when various medium tanks were usually armed with anti-tank guns, but some were equipped with low-velocity high-explosive-yield howitzers (sound familiar?) and tasked purely with infantry support.

Now you can make a case of:

HE + STAFF or

AP + HMG or

Sabot + LMG

and not feel too gimped while fighting a variety of targets.

You can still specialize anti-vehicle with Sabot + STAFF, or specialize close-in anti-infantry with HE + LMG. Point is, they're all viable now, provided you know what you want to do.

DPS against vehicles is approximately the same across shells. They are not particularly disadvantaged against any vehicle.

Old HE shell had the worst DPS against vehicles by far, and terrible splash damage, worse than even sabot. It also had terrible velocity, which meant it could be easily dodged, and the high drop meant that at longer distances your damage would start to drop due to angle modifiers. The only real advantage it had was higher single hit damage, and thus larger crit zones, however this was almost entirely negated by any tank driver that understands angles.

The new HE shell has the best blast damage of the three shells, has faster reload and auto replenish so it can output that blast damage more often, and using shells against infantry is less costly if you get engaged by a vehicle shortly afterwards. It has the same velocity and drop as AP shell. Its DPS against vehicles is only marginally lower than AP/Sabot, and much higher than the old HE shell. Its biggest disadvantage is low single hit damage, which means crit zones are small and it can be difficult to land mobility hits.

HE is best used in any map that has fewer vehicles and more infantry. I like to run it on Operation Outbreak since there's only 1 enemy tank and 1 enemy IFV while there are a lot of infantry. The extra splash and faster ROF helps against infantry, and the faster ROF and replenish speed give it competitive DPS against vehicles. Since infantry are the primary threat on Outbreak, I tend to run HE there.

Compared to the AP shell, the HE shell puts you at a pretty significant disadvantage vs. other tanks in exchange for a fairly marginal advantage against infantry. Although the faster reload largely offsets the lower damage the fact that you need to land one more shell to destroy a tank (on any side) than you would with AP / Sabot is a major disadvantage when you're up against a tank that knows how to pillar effectively. And if he's getting reps it's even worse.

I don't see that the marginally higher splash damage (1.88 m OHK radius vs. 1.5 m with AP shells) and effective reload time (3 s vs. 3.5 s) is worth gimping yourself against other tanks. It seems to be mainly geared towards STAFF shell users who don't want to be so weak vs. infantry. I don't see why anyone else would want to use it unless they were playing a very infantry-heavy map (e.g. Zavod, Op. Outbreak) or the enemy team doesn't have any decent tank drivers.