There are two possible visual regressions introduced by #4191
When a notice appears at the bottom of a mobile screen, the 'X' now displays in the bottom left instead of top right
Before #4191

After #4191

On an iPhone 6+ screen size (4.7"), the published post message displays on two lines, although it appears that this would fit on one line:
Before #4191

After #4191

cc: @Tug
On an iPhone 6+ screen size (4.7"), the published post message displays on two lines, although it appears that this would fit on one line:
This wouldn't always fit on one line depending on the user's language setting and also length of site name. #4191 allows more flexibility for length of copy.
The 'X' button issue is also relevant to notices at the top of the screen. Eg. updating a user's role:

Thanks for reporting @alisterscott! My bad, I forgot to test those!
Thanks, retested all good :+1:
Most helpful comment
This wouldn't always fit on one line depending on the user's language setting and also length of site name. #4191 allows more flexibility for length of copy.