Comment by nimih

They didn't say you "might" be able to use it under the AGPL, but that you "may" be licensed to use it. Which, as a native speaker of American English, seems to be relatively clear in its meaning along the lines of what the GP poster stated. Of course, the various meanings of "may" in English might be subtle enough that I'd readily believe it's less clear to non-native speakers (or maybe even speakers of a different dialect), and it's unfortunate that Mattermost's lawyers aren't interesting in cleaning up the language.