Comment by CoastalCoder

I grew up in New England.

My experience is that "thuh" is basically a lazy / informal pronunciation of that word.

But it's also by far the most common pronunciation. "Thee" would sound strangely hyper-formal, at least in my circles.

Edit: the sibling comment (https://news.ycombinator.com/item?id=49770609) also rings true to me.