BASE RATE
@Akkete found dates that would seem to indicate the opening dates of various OTICs.
13 OTICs were inaugurated in August 2021 or later, they combined for roughly 5,300 working days and produced 2 certificates.
There are 8 OTICs in North America which will work for roughly 2,800 days between now and the end of the question. The base rate chance to see a certificate coming out of them would be 65%.
This approach completely ignores all the OTICs that were already operating before August 2021 and all the certificates they released. The assumption is that there is a lead time between the beginning of operation and the release of the first certificate: not knowing when they started operating might significantly skew the results.
The Japanese OTIC released its first certificate 178 days after beginning operation, and the Korean one after 464 days. It would be pointless to extract any meaningful signal from this data, but at least we know that all the North American OTIS have been operating long enough to be plausibly releasing certificates today.
FURTHER CONSIDERATIONS
12/13 of the certificates have been released by Asian OTICs and that's a fact. The reasons are unclear to me. National security and business interest, as suggested by @PeterStamp, are certainly two valuable hypotheses. But one could make a broader point about some base rate "population" statistics: how much each country invests in R&D? How much of the GDP comes from telecom companies? How many large telecom companies and start-ups are working on these issues?
This brings me to my second consideration. 8 OTICs have been opened in the US, all during 2023. This has to be justified by the existence of a significant demand for the services they offer, and certifications are one of such services. If the O-RAN community wanted to simply establish a footprint in the US, they could have opened a single center, as seems to be the case for most countries. The almost simultaneous opening of 8 centers in NA is significant in this regard and might be interpreted as making this question more likely to be resolved positively.
After all, the number of start-up companies in the US dwarfs that of any other country and they cumulatively output massive technological advances. So it is plausible that some of them are currently working to get one of those certificates.
Edging slightly higher after researching the Huawei question. The US are investing a lot in the O-RAN technologies, so I wouldn't be surprised if some start-up emerges to capitalize on the opportunity.