Raducanu being out in round 1 is a real possibility with an opponent like Cornet. Same with Muguruza vs. Tauson.
Muguruza could go out in the first round against anyone. I really feel for her fans; they must get whiplash following her career.

I'd like to see Serena preserve her perfect record in the first two rounds, but I expect little of her beyond that. Emma has a huge task on her hands. As does Naomi, but that's kind of what you get for hardly playing all year.
The way everyone’s expecting Serena to just play the one match is killing me… it shouldn’t end like this!
Me too. It really shouldn't. Especially when you consider that the last time she played and didn't at least make the semis was in 2007!

That said, her appearances this season have been underwhelming. I respect her reasons for walking away and think that she has the right to go out any which way feels right for her life balance at this point... but I can't help but (selfishly) wish that playing this swing felt like less of a whim and that she'd prepared better. Watching her struggle has been gut-wrenching.
This probably wouldn’t be popular among Serena’s fans (of which I count myself), but honestly, I loved her match at Wimbledon and it should have been her last. It had everything. Other-worldly shotmaking, heart-crushing errors, a crowd wildly cheering for Serena (which hasn’t always been the case), momentum swings, classic serving, it was pure drama and entertainment. It had the essence of everything that makes Serena great.

The two matches she’s played since the Vogue essay was released have been difficult to watch, and I’ve been really surprised she’s gone out there on a farewell tour at all. It’s uncomfortable, it’s the type of thing I’d expect Roger to do, to take in all the endless adoration. If it is just the one match next week, I hope at least she’s simply outplayed and not just going through the motions like she was against Raducanu.
The defeats by Sharapova and even Kanepi were understandable, but she shouldn't be losing to a qualifier who's never won a tour-level match before. Properly embarrassing.
It’s weird, because she played under the radar last year and honestly was in a dark horse position until she blew it against Svitolina, but today was a proper meltdown. It feels mental more than anything.
An example of the recent rule change for coaching at the US Open today during Sakkari’s 1st round match:

I had somehow totally missed this rule change (and was having issues with my in-ear radio, so missed any commentary on it) and couldn't believe how flagrant the coaching was during this match and also the Keys/Yastremska match. Guess the umpires aren't as blind/incompetent as I thought they were...

What a great night for Serena -- there were moments of near-vintage form towards the end of that second set, which it was wonderful to see her do again. The crowd was really behind her. Lots of tears in my section during her pre-match introduction and during the ceremony afterwards.