Let's get one thing straight, Thai is still a member of Star.
I'm not going to say too much except at the Star meeting in Japan a few months back (the intro of ANA), quite a few exectutives were commeneting on safety matters and how that relates to the Star Alliance.
While they didn't say names, it was obvious who they were talking about...TG.
I don't think there could be too much said about Star not cooperating, TG is very close to LH and SK (SK's ties go back a long way...). However, if they do leave, SQ's entry would probably be a major factor. But frankly, SQ is more an asset than TG in all honesty.