i think it could go 3 ways.
1. is a general army expansion. maybe a new trogg, new stabbas, an armored grot knight unit.
2. is increase the gitmob stuff. more wolves and plains grots, give them a hero and a chariot.
3. is a spider refresh/expansion to make them fit into the army better.
i think 2 is the most likely personally but i also would like it the least; GSG is one of the most thematically rich and congruent armies in the game (even with Spiderfang) and i think that the Gitmob stuff sticks out like a sore thumb. it's not bad, but i'd so much prefer if it was just it's own army without being forced to cross-pollinate with a completed army. 1 would be nice; GSG doesn't really need this but i mean i'll take it. 3 would be ideal, both by replacing old models but also working out the last few kinks in the army's aesthetic and really expanding on the insect theme of GSG which i think is wildly under-utilized.