I would, for selfish reasons, like to see MH join OW.
However, I don't think it is likely, as MH wants KUL to be a hub, while QF already uses SIN and BKK as transit points for SEA. Also, MH would be competing with QF for passengers on the Kangaroo route, as they fly from most Aussie cities to KUL, and then KUL to LHR.
Also KE is also unlikely to mind MH joining ST, as their routes would complement each other (North and Southeast Asia). However, CX has a relatively greater network than KE in SEA, and might not want a competitor in the region. e.g. AA passengers who want to go to KUL now have to go via HK on OW. If MH joins OW, they could fly LAX-KUL directly on MH. nd on to other Southeast Asian destinations.
Additionally, MH already has relationships with many of the ST members.
But, who knows? It would be good for us if MH joins OW.