Verdi opera I've never heard of, but it's got a lot of common letters, including the first three vowels, so here we are
16A
"Don't think so!"
17A
Your only brother's only nephew
18A
"Is Antony ___ in fault for this?" (Shakespeare)
20A
Eagle that's not part of the meta
25A
She played Lilith on "Cheers"
26A
"Knives Out" actress de Armas who never but could have said, "Thanks, I love being in crosswords all the time"
27A
A real humdinger
30A
"Sleepless in Seattle" director
32A
They're where the action is
34A
"Did you solve the impossible Week 7 meta?" "___"
35A
"Romantic" introduction?
36A
Using too much crosswordese in a puzzle, perhaps
37A
First name of actress whose second role (after a record-setting first) was in 1976's "The Bad News Bears"
38A
Business for them is blowing up: Abbr.
Verticales
1D
Mikey G, compared to all other crossword writers
2D
Pith
3D
"No clue" (Wait, this has no clue?) (No, "No clue" is the clue) (So who's on first?)
4D
Author Janowitz (who has two of the same vowel in her name)
5D
Half of a dance
6D
I'll see him in court
7D
Abolitionist and suffragist Sarah
8D
"And the first came out red, all over like an hairy garment; and they called his name ___" (Genesis 25:25)
9D
___ Tzu
11D
Most ideal position if you didn't win and you're not the runner-up either
15D
Second word in name of band who wrote a song with the phrases "bearded barley," "milky twilight," and "broken treehouse" (not meta-related, I just think it's poetic)
19D
Shed a lot?
21D
Operating system named after an African philosophy