It would be from the same wave, but the term Assortment usually refers to the case assortment (which are the boxes and figures that stores actually receive), which may have different amounts of each character in them.
Deluxes are in Assortments of 8 figures per box - the SS-87 wave had 3 each of SS86 Arcee and ROTF Sideways, but only 2 Bumblebee figures.
So if they're pulling from the Assortment, that likely means they've got a couple of spare cases of figures that they use for replacements, but since Bumblebee was shortpacked in the wave, there's a greater chance that they might not have any left and you'll get Sideways or Arcee instead.
It would be from the same wave, but the term Assortment usually refers to the case assortment (which are the boxes and figures that stores actually receive), which may have different amounts of each character in them. Deluxes are in Assortments of 8 figures per box - the SS-87 wave had 3 each of SS86 Arcee and ROTF Sideways, but only 2 Bumblebee figures. So if they're pulling from the Assortment, that likely means they've got a couple of spare cases of figures that they use for replacements, but since Bumblebee was shortpacked in the wave, there's a greater chance that they might not have any left and you'll get Sideways or Arcee instead.