That was the whole point!
I think I found it. I should just replace
-2x.png in the welcome message. Then I had to tweak the sizes of some images. Now it works OK for me.
The English version of the copy has the correct widths and heights in the markup; use those. Copy the whole
a href over.
The problem arises with the customized messages that rely on the old images:
It is obvious customized messages cannot be updated automatically, so why would you make the images unavailable at some point in time.