The brs don't stop you putting it into the payload. If you remove them you will just have a long string with them removed. What exactly do you want to end up with?
in theory msg.html should contain the html version and msg.payload the plain text version - but that will depend on the sending end and it's not always the case (but worth checking). As noted you could use the html node - but you could also use the split node (which would produce a series of messages rather than one array) - or a change node to replace <br/> . or a function node with a small bit of code to slice it however you like.