First off, thank you to Yair Lichtman, my teacher and friend, for explaining to me this great idea. No, seriously, it's a great idea. And it's not called bragging if you do it for other people.
Next up: If I asked 100 people on the street what happened to Vashti, maybe ninety-nine would say she was killed. This is a midrash, but it is a well-known one. Additionally, the story of Vashti is in a book full of midrashic interpretation that is sometimes treated like peshat. We're going to be defying many of those midrashim today. So, buckle your seat-belts and enjoy the ride!
(ט) גַּ֚ם וַשְׁתִּ֣י הַמַּלְכָּ֔ה עָשְׂתָ֖ה מִשְׁתֵּ֣ה נָשִׁ֑ים בֵּ֚ית הַמַּלְכ֔וּת אֲשֶׁ֖ר לַמֶּ֥לֶךְ אֲחַשְׁוֵרֽוֹשׁ׃ (ס) (י) בַּיּוֹם֙ הַשְּׁבִיעִ֔י כְּט֥וֹב לֵב־הַמֶּ֖לֶךְ בַּיָּ֑יִן אָמַ֡ר לִ֠מְהוּמָן בִּזְּתָ֨א חַרְבוֹנָ֜א בִּגְתָ֤א וַאֲבַגְתָא֙ זֵתַ֣ר וְכַרְכַּ֔ס שִׁבְעַת֙ הַסָּ֣רִיסִ֔ים הַמְשָׁ֣רְתִ֔ים אֶת־פְּנֵ֖י הַמֶּ֥לֶךְ אֲחַשְׁוֵרֽוֹשׁ׃ (יא) לְ֠הָבִיא אֶת־וַשְׁתִּ֧י הַמַּלְכָּ֛ה לִפְנֵ֥י הַמֶּ֖לֶךְ בְּכֶ֣תֶר מַלְכ֑וּת לְהַרְא֨וֹת הָֽעַמִּ֤ים וְהַשָּׂרִים֙ אֶת־יָפְיָ֔הּ כִּֽי־טוֹבַ֥ת מַרְאֶ֖ה הִֽיא׃ (יב) וַתְּמָאֵ֞ן הַמַּלְכָּ֣ה וַשְׁתִּ֗י לָבוֹא֙ בִּדְבַ֣ר הַמֶּ֔לֶךְ אֲשֶׁ֖ר בְּיַ֣ד הַסָּרִיסִ֑ים וַיִּקְצֹ֤ף הַמֶּ֙לֶךְ֙ מְאֹ֔ד וַחֲמָת֖וֹ בָּעֲרָ֥ה בֽוֹ׃
(יט) אִם עַל הַמֶּלֶךְ טוֹב יֵצֵא דְבַר מַלְכוּת מִלְּפָנָיו וְיִכָּתֵב בְּדָתֵי פָרַס וּמָדַי וְלֹא יַעֲבוֹר אֲשֶׁר לֹא תָבוֹא וַשְׁתִּי לִפְנֵי הַמֶּלֶךְ אֲחַשְׁוֵרוֹשׁ וּמַלְכוּתָהּ יִתֵּן הַמֶּלֶךְ לִרְעוּתָהּ הַטּוֹבָה מִמֶּנָּה.
(19) If it please the king, let there go forth a royal commandment from him, and let it be written among the laws of the Persians and the Medes, that it be not altered, that Vashti come no more before king Ahasuerus, and that the king give her royal estate unto another that is better than she.
(1) After these things, when the wrath of king Ahasuerus was assuaged, (A) he remembered Vashti, and (B) what she had done, and (C) what was decreed against her.
(A) It says that he misses Vashti, specifically. Also, (B) Achashverosh remembers what he decreed- Vashti cannot be restored to the throne. You may think that he can just annull the proclamation. However...
(ט) כְּעַן מַלְכָּא תְּקִים אֱסָרָא וְתִרְשֻׁם כְּתָבָא דִּי לָא לְהַשְׁנָיָה כְּדָת מָדַי וּפָרַס דִּי לָא תֶעְדֵּא.
(12) But the queen Vashti refused to come at the king’s commandment by the chamberlains; therefore was the king very wroth, and his anger burned in him.
But wait, you say. Doesn't Esther biography dispute the connection?
(7) And he (Mordechai) brought up Hadassah, that is, Esther, his cousin; for she had neither father nor mother, and the maiden was of beautiful form and fair to look on; and when her father and mother were dead, Mordecai took her for his own daughter.
1: In the first time the verse talks about Esther's parents, it does not say that they died. It says that she doesn't have any parents. What is the only type of person who, according to halacha, lacks parents? A convert to Judaism.
2: The term 'cousin' is almost completely meaningless. In biblical times, the language of familial ties was much more fluid. 'Father' could mean just that, or a grandfather, or any mentor. And seeing as all of Bnei Yisrael are cousins, this may only tell us that Vashti had converted.
Saying that Esther was a convert also solves another problem:
(17) And the king loved Esther above all the women, and she obtained grace and favour in his sight more than all the virgins; so that he set the royal crown upon her head, and made her queen instead of Vashti.
(יב) דבר אחר: פרי עץ הדר, אלו ישראל. מה אתרוג זה, יש בו טעם ויש בו ריח. כך ישראל, יש בהם בני אדם, שיש בהם תורה, ויש בהם מעשים טובים. כפות תמרים, אלו ישראל. מה התמרה הזו, יש בו טעם ואין בו ריח. כך הם ישראל, יש בהם שיש בהם תורה ואין בהם מעשים טובים. וענף עץ עבות, אלו ישראל. מה הדס, יש בו ריח ואין בו טעם.כך ישראל, יש בהם שיש בהם מעשים טובים ואין בהם תורה...
(12) Another explanation: "The fruit of a beautiful tree" - these are [referring to] Israel. Just like this citron (etrog), which has taste and has smell, so too Israel has among them people that have Torah and have good deeds. "The branches of a date palm" - these are [referring to] Israel. Just like this date, which has taste and has no smell, so too Israel has among them those that have Torah but do not have good deeds. "And a branch of a braided tree (a myrtle)" - these are [referring to] Israel. Just like this myrtle, which has smell and has no taste, so too Israel has among them those that have good deeds but do not have Torah...

