I think it meant it's now a bundled "gem", but "is now bundled" implies
it's a new gem that was neither default nor bundled gems. So I changed
wording.

I also want to change the subjects and reorder them so that it will read:
"The following default gem" (new) -> "The following default gem" (updated) ->
"The following bundled gem" (new) -> "The following bundled gem" (updated).

in tool/update-NEWS-gemlist.rb