Nope. You can get get stock into the market pretty easily. I'd guess that at least 50% of all Pinks don't have any registered stock.
The registration process is complicated and can be quite expensive. Registration forms like the S-1 and S-2 have to be deemed effective by the SEC before the stock can be registered and sold. That usually takes quite awhile. Up to a year or more. So they decided to make the process easier for small companies.
Maybe not a bad idea in theory, but the reality hasn't worked out so well. Doing it seems to be as easy as getting yourself incorporated and getting an MM to file a Form 211:
How Do Companies Get onto the OTC Market?
Because it is not an exchange, companies do not choose to be traded on the OTC market. Broker-dealers decide which stocks to quote for best execution of their customer orders. There are 3 ways that securities begin trading in the OTC market:
A broker-dealer files a Form 211 with FINRA in order to begin quoting the security on an interdealer-quotation system. This method is generally used for companies that have no history of trading in the public markets or to begin trading again after a lapse in trading. See Get Quoted.
De-list from an exchange. When a security is delisted from an exchange, the trading in the stock generally moves to the OTC market. See FAQ on Delisting from an Exchange.
Reverse merger into a shell company already traded OTC.