A servant talks to his master when they see the movie star on TV.
I am wondering if the bold part means "used to be a fan of 柊しずか" or reeks a confirming tone as in "今日は晴れでしたね."
Could you share your thoughts?
I think it is confirmation. If it were meant to be "used to be a fan," the servant raising a question to his master's behaviour is odd. He should be knowing that the master isn't a fan any more, which is the entailment of "used to."
A few half-baked words about the confirming -ta. The tense/aspect particle functions as the confirming agent of the speakers conviction, while morphologically it combines with the verb denoting the action of someone other than the speaker. Underlying this construction is the following semantic form (not necessarily shows the syntactic derivation):
The tense/aspect of the main clause overrides that of the subordinate clause.