Cantoresq-
You echo the sentiments of Chazal, that clearing doubts brings relief/joy. I don’t think they specified that relief depends on the outcome of the resolution, only that the doubts are resolved.
The extent of the resolution of doubts probably determines the extent of the relief.
After this ex-rabbi pledged his allegiance to G-d for so many years, I am skeptical that “Shema Yisroel” won’t resurface to threaten his psychological liberation.