The NEW style of 26" charcoal grate fits in the old 26" grills, but it doesn't sit on the tabs. It's relatively secure - not perfect, but it's not going to tip completely over or anything.
The new charcoal grate sits about 1.5 inches higher than the strap where it should sit.
And since this discussion has come up before, here is how the Craycort 26" cast iron sits. It also sits ABOVE the straps where the cooking grate should be.
It wedges in there and remains pretty stable. By no means perfect and it may move a little if you brush really hard. The craycort sits more stable than the standard new style of 26" cooking grate, likely because of the weight and shape of the edges.
Sorry no pics of new style cooking grate, it's burried in my garage of doom