Thats pretty much what I was thinking, although what got me thinking is what you would say. A go around instruction from ATC is very direct and the pilots are aware that on an approach there is a possibilty of such and so could/would expect it anyway and will initiate very succinctly. Where as a blind call from another aircraft, indentifying its self and making known the problem might not have the same impact and result in a delayed reaction.
And modelman you say "singout", which I agree with , but if the situation was critical ( moments before touchdown )would it be concievable for the pilot at the holding point to make a blind "go around" call if it potentially save the day?!