Does language help someone access their heritage culture? Definitely. Does it help someone do so at a "deeper" or "better" level than food or family values or ritual? eh.

I'm a second gen Indian who doesn't speak Gujarati (partly because my parents, though both Gujarati, usually spoke English to each other; long story.) And I've always felt bad for not being able to speak it or any other Indian language with any fluency. I definitely tend to think that language = culture, so it's really interesting to see this perspective!