The product page shows what it looks like when all 12 plush animals are assembled, though it takes immense effort to get them to sit upright like that without using the magnets in their cheeks for support.
The newest members of the sitting plush series are Orologia (M) and Orologia (F)! Male Orologia sits at 20 cm tall, while the female Oro is only slightly shorter at 18.5cm. Each is sold separately, for 4000 yen each.
I think people would have been willing to eventually move on if the heavy update, and maybe one more "The Finale," update came out. TF2 ending on the promise of at least one more update is what makes it feel so upsetting.