“As to DY’s skepticism of Rav Tendler’s credibility, I’ll repeat my original admonition to take anything attributed to anonymous internet sources with a grain of salt.”
Meaning we should be skeptical of it, yet our skepticism seems to bother you. Was it a hollow disclaimer?
If you take the greater Rav Tendler controversy out of the question, the story still makes no sense as you presented it. It seems to say that behind closed doors, Reb Moshe held like the Pri Chodosh, and his teshuvah is just something he told to the masses. There’s no reason to believe he would do that.