The official Neptunia anime Twitter has announced that there will be a Thanksgiving OVA in the works, with a Space Harrier-inspired game known as "Top Nep" and a scale figure of the older Neptune's new costume to coincide with the game.
A prototype of the figure will be showcased at Wonderful Hobby 34 from October 2nd to October 10th. More info here: http://whl4u.jp/
Page for said OVA is up:
And Top Nep is coming to Steam in early 2022: