Should this be wrapped in a function to provide an easier to understand stack trace if this ends up throwing?

I could, although I find it more confusing to have static methods that are called before static initialization completes. It's necessary and helpful at times, but when unnecessary I try to avoid it as I find it to be bug-prone.

Do we expect the IllegalStateException to be caught somewhere? It looks like in the current flow this propagates back through the NettyChannelBuilder, in which case it seems a little confusing to say "(this may be normal)" for all of these when we're about to fail. I think the intent is that it might be normal for two out of the three to be missing, but the current message seems to imply it's ok for all of them to be missing. Maybe add an initial "One of the following TLS ALPN providers must be available:" log statement and drop the "(this may be normal)" text?

Spoke offline. The main reason I didn't do that is because then the error is reported in two places: the log message and the exception. Right now the log messages are just informational and it's only after you get the exception that you can look at them and think "these might be useful."