And C-x C-e and look at ~/org.ical, it is what I expect. If I change "nil" to "t" and re-execute that line, it contains items tagged "noexport".
I tried to give an MWE, but perhaps it wasn't well prepared. I'm happy to debug this via email (I'm pretty sure we're making progress). But if I can provide a better MWE org file I am happy to do so. Please let me know how to improve the provided bug report.