Since Talmudic times, Rabbinic scholars have grappled with the apparent contradiction between the Biblical and/or Rabbinic prohibition(s) of chodosh (new grain grown since Passover) and the common Ashkenazic practice in the Diaspora to ignore the issue. The Talmud (Menachot) records that there was a dispute between Tannaitic and Amoraic scholars regarding whether chodosh outside Israel is forbidden biblically or Rabbinically. The overwhelming majority of the most prominent post-Talmudic authorities ruled that the prohibition is biblical in nature even outside Israel (e.g. Maimonides, Rif, Rosh, Shulchan Aruch, Ram"a, Ba"ch, Gr"a, Sha"ch, Ta"z) which means that even an equiprobable uncertainty (safek hashakul) would be completely forbidden. (Further, following the Maharshal, Rav Moshe Feinstein doesn't even allow relying on a majority to be lenient.) Nonetheless, the common practice continues to be one of leniency.
In Europe, one justification of the practice was suggested by the Ba"ch who argued with both those who preceded and those who followed him and claimed the prohibition only applied to Jewish-owned grain. This approach appears to be the one adopted by the Hassidic community following a story in which the Baal Shem Tov was temporarily lenient because of the Bach allegedly appearing to him in a dream.* Nonetheless, this leniency is widespread in even the Mithnagdic community that generally would follow the Rama (who follows the Ro"sh and maintains it's a biblical prohibition regardless of ownership).
This leniency of the Bach is almost universally rejected, including by his son-in-law, the Taz, who instead suggests that b'shaat hadechak (in time of pressing need), there is room to be reliant on the minority Tanaitic position that the prohibition is only Rabbinic, thus allowing leniency in cases of safek hashakul.** The Shach rejects this leniency as well since the Talmudic dictum upon which the Taz is based "kdai hu Rabbi Eliezer lismoch alav bshaas hadechak ("Fitting is Rabbi Eliezer to rely upon him in time of duress") never appears where the majority position was that the prohibition is biblical in nature. The Taz is however relied upon by Rav Nachum Rabinovitch, shlitah, in his responsa sefer Siach Nachum. Nonetheless, it seems fairly self-evident that even the Taz would be strict in a city where yoshon (grain that rooted before Passover) alternatives are cheaply and readily available, such as in New York and its suburbs.
Another leniency is suggested by the Aruch HaShulchan to be used in combination with other leniencies, based on the recently unearthed rulings of the Ohr Zarua. He justified the already common practice by suggesting two stacked chiddushim: 1. that the lenient communities traditionally followed the minority Tannaitic position, and 2. that that position only forbade (even Rabbinically) chodosh in lands near Israel. (Presumably, this distance included Jewish Iraq/Bavel since even the Amoraim who were lenient there with regard to biblical law, kept the Rabbinic prohibition.) My understanding is that this position is what is relied upon by Rav Herschel Schachter, shlitah, and (more recently) by Rav Mordechai Willig, shlitah.
(Well that was a mouthful...)
My questions are:
To my understanding (please correct me if I am wrong), the O-U uses a majority rule of their 3 poskim, shlitah: Rav Schechter, Rav Yisrael Belsky, and Rav Menachem Genack. Rav Belsky and Rav Genack are themselves machmir (strict).
So what is the reasoning behind the O-U's certification as kosher of products that are possibly/probably/definitely chodosh (particularly considering their stringent positions even beyond the letter of the law with regard to certifying other issues - e.g. relying on rov-majority)?
Similarly, do Rav Schechter and Rav Willig reject the majority position of the mainstream Rishonim and Achronim, even in places and/or for persons for whom it is not a shaat hadechak? What is the basis for rejecting the majority and mainstream positions based on an at best speculative retrospective claim that the communities' authorities were lenient? Considering we no longer (and perhaps never) lived in the communities of the minority/non-existent lenient position, why would we not now follow the majority?
Further, inasmuch as these practices were used in a post-hoc, minhag-justifying, shaat hadechak manner in a climate where the masses were unlikely to have heeded a stringent ruling (see e.g. Rama citing Rosh), what justification is there to be lenient nowadays for those who are strict for even more tedious and more minor stringencies?
Finally, is there any other argument used by kashrut agencies to justify their certification of chodosh, when they are strict on other seemingly far more minor issues?
*(I'm not sure how this reliance shouldn't be a violation of the Midrashic interpretation of "lo bashamayim hi;)
**The Gr"a also uses unusually harsh language in rejecting his great-great-great-grandfather the Be'er HaGolah's lenient position, arguing that it would have been if he had never written it.