CALP was written quite some time ago. Is it possible almond milk wasn't included because it wasn't as popular then as it is today? Or does it state somewhere specifically that it isn't included?

I don't drink it myself. lol

It was written some time ago, but it has lists of cm items, and if not on those lists, one is not supposed to eat the unlisted food outside of rm. In a slightly later book - their heart healthy book, they specificially say that all nuts are considered high carb and not to be eaten outside rm..almond milk would def. fall into that category.

One can choose to not strictly follow their plans, but I was answering the question based on their plans as written