Additionally, but not critical:

I think for syncs that happened yesterday, a more friendlier syntax would be:
"XX:XX Yesterday"

Chris, PTAL. I think it should be a straightforward fix :)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3ab6dcb4843d3cd6c435f7d2f6b3e32dc2feec57

commit 3ab6dcb4843d3cd6c435f7d2f6b3e32dc2feec57
Author: Chris Lu <thegreenfrog@chromium.org>
Date: Thu Aug 16 23:07:49 2018

[ios] Don't show day if time synced is today or yesterday in Recent Tabs

Removes the date for sync times that occur within the same calendar day. Replaces date with "Yesterday" for sync times that occur in the previous calendar day.

Screenshot: https://drive.google.com/open?id=1uFZHxOgHytaARm97MWONgekuymVxRBvJ, https://drive.google.com/open?id=1ZZr5HR___1y_CuQKcoNP-5Umd2Lz5K3n

Bug:  870043 
Change-Id: Id6d4ecb424d5e709e66e48cd57d0c4add5683b1c
Reviewed-on: https://chromium-review.googlesource.com/1177891
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583871}
[modify] https://crrev.com/3ab6dcb4843d3cd6c435f7d2f6b3e32dc2feec57/ios/chrome/app/strings/ios_strings.grd
[modify] https://crrev.com/3ab6dcb4843d3cd6c435f7d2f6b3e32dc2feec57/ios/chrome/browser/ui/recent_tabs/recent_tabs_table_view_controller.mm

Verified on iPhone X iOS 12 Beta9 , iPhone 6+ iOS 11.4, iPhone 7+ iOS 10.3.3 
Date is not show when the sync happens on the same day - https://drive.google.com/file/d/1Cinzbd1Ga8kzc8S0zqAMKqTJXIXZU3ls/view?usp=sharing

But on iPad Pro 12'9 iOS 11.4.1 The date is shown.
https://drive.google.com/file/d/1kg2c3tLH1iuH_dK9vQzIHoh1cLF45W9I/view?usp=sharing
This is the first device that was signed into for sync.

I find it really hard to believe that the behavior is different on an iPadPro, since the logic for adding those strings is gone and has nothing to do with UI.

Are you sure you were using the latest Canary on that iPadPro? 

Can we get confirmation + vbhatsoori that this is still an issue? Thanks!

Tested on new Canary.ipa . I am no longer able to repro this issue. Hence closing it as Verified.