Lots of companies have been forced to do provide free services to non-customers; consider almost any industry classified as a 'utility'. The question here is 'are message platforms a thing that should be classified and regulated as if it were a utility?'
For me, the answer is clearly no; there are plenty of communication platforms that can be used freely with interoperability (e.g. email). And, as you note, there are lots of interoperable options.
For me, the answer is clearly no; there are plenty of communication platforms that can be used freely with interoperability (e.g. email). And, as you note, there are lots of interoperable options.