No matter if the campaign is running or not, no matter if billing is added or not, if the existing ad copy is about bananas and you change that to something else (example watches), then obviously that will nowadays trigger an account suspension.
Even sentence structure in ad copy can trigger an account suspension. Do not forget that Google Ads algorithms use automation (AI) to understand the ad copy (ad headlines, ad description), so the way sentences are structured in the ad copy can also trigger Google Ads algorithms to suspend an account .... and the same goes with landing pages (in a search campaign).
No matter what people say, in 99% of accounts suspended where the reason shows as due to suspicious payment, in reality it has NOTHING to do with payment or card or billing. (I understand that you did not yet setup billing, though .... Your account was suspended because you pissed off Google Ads algorithms, with the change that you did in your campaign's ad copy. It is as simple as that.)
