Valve doesn't manufacture Steam Machines, OEMs do. Are the OEMs making their money back? Well, Valve has disclosed that 500k Steam Controllers have been sold (as the article notes) which is a hard upper bound on the possible number of Steam Machines sold since each Steam Machine comes with one Steam Controller. Practically speaking, probably less than a third of them actually sold with Steam Machines and that third is spread across all the OEMs making Steam Machines. So, no, probably not enough to make it worthwhile for any of them.

Valve isn't a public company so they're not obligated to provide any financial data, meaning that there's none available for deeper analysis.