The Baal Haturim brings on Shemos 14:20 וַיָּבֹ֞א בֵּ֣ין ׀ מַחֲנֵ֣ה מִצְרַ֗יִם וּבֵין֙ מַחֲנֵ֣ה יִשְׂרָאֵ֔ל וַיְהִ֤י הֶֽעָנָן֙ וְהַחֹ֔שֶׁךְ וַיָּ֖אֶר אֶת־הַלָּ֑יְלָה וְלֹא־קָרַ֥ב זֶ֛ה אֶל־זֶ֖ה כׇּל־הַלָּֽיְלָה a very interesting Midrash from Megillah 10b
מַאי דִּכְתִיב: ״וְלֹא קָרַב זֶה אֶל זֶה כׇּל הַלָּיְלָה״ — בִּקְּשׁוּ מַלְאֲכֵי הַשָּׁרֵת לוֹמַר שִׁירָה, אָמַר הַקָּדוֹשׁ בָּרוּךְ הוּא: מַעֲשֵׂה יָדַי טוֹבְעִין בַּיָּם, וְאַתֶּם אוֹמְרִים שִׁירָה
What is the meaning of that which is written: “And the one came not near the other all the night” (Exodus 14:20)? The ministering angels wanted to sing their song, for the angels would sing songs to each other, as it states: “And they called out to each other and said” (Isaiah 6:3), but the Holy One, Blessed be He, said: The work of My hands, the Egyptians, are drowning at sea, and you wish to say songs?
He adds to it a very interesting comparison with the verse Isaiah 6:3 וְקָרָ֨א זֶ֤ה אֶל־זֶה֙ וְאָמַ֔ר קָד֧וֹשׁ קָד֛וֹשׁ קָד֖וֹשׁ That is, the same ones who usually call to one another to sing Shirah, this time were not allowed to approach one another to do it. [The Maharsha makes the same suggestion in Sanhedrin 39b.]
My problem is, How does this fit with what seems to be the simple reading of the verse: "Because of the pillar of cloud, the army of Egypt and Israel were kept separate from one another that night?" It sounds very unrelated. So a general question: (a) Should Midrashim be assumed to reflect a deeper but still connected aspect of the simple Pshat? [sources?] And a specific question: (b) If so, is there a way to explain that here?