I don't know how people still think this is a Spriggan. It's quite easy to determine this is Achilles. The Two swords are going upwards like Achilles's design. The two typical "shields" between the swords is also easily visible which follows Achilles' design. Also, the next few episodes of the anime are centered towards Legends' Festival and Aiga's debut so Achilles is obviously going to be this release.
It makes sense why Spriggan will be in that Random Booster on October. Also for the parts I do expect a new double chassis in Achilles (2B?) and possibly Dimension'.
TBH, I don't think it's going to be another xtend or xtend+ with other variations. They can easily plot a Dimension' as it was originally released in the previous Achilles. PLUS, There is NO other bey to follow the same driver of it's previous generation besides a few exceptions such as Cho-Z Spriggan and Mad Minoboros. (Cho-Z Spriggan cuz they were lazy to make another new driver for Spriggan, and Minoboros cuz they didn't have another jumping driver back then before Operate even came out.)
you better watch this if you want nostalgia over these years. MEP Legendary:
https://youtu.be/BxXAlIpZ-ns