I know companies that go public on the OTC via IPO(S1), non shells/RMs, likely need the 2 years audited financials, however, they don't necessarily need to 'trade' per se on the OTC if they don't want to.
For example BTBD just moved to Nasdaq, they filed their S1 back in 2019 and were on the OTC, even changed tiers from Pink to QB.... but never actually traded even a single share as an OTC company, they waited for Nasdaq to start trading.