it comes down to how you define payola, since it's definition has been warped by crazy stans. It is defined as: Payola, in the music industry, is the name given to the illegal practice of paying a commercial radio station to play a song without the station disclosing the payment.
How kpop stans define it is basically just any type of paid promotion by a label (playlisting, ads, etc).
So by the actual definition of payola, no. By the made up one, yes, but obviously companies invest money in their artists, not really rocket science. It doesn't change the fact that NewJeans is still a massively popular group and I would guess any % of their perceived success that comes from "payola" is low, but we'll never know what that % is and it doesn't matter.
Each time the word payola is used my brain rots a little more and I weep for the state of the kpop community. It's just so stupid and a cheap way to bring down successful groups. Labels pay for promotion, that's never going to change, and the bigger labels are gonna be able to pay more. People are still listening to the music and they are reaching new fans, so who gives a shit.