Generally when we send confirmation emails to addresses the user has
not already proven that they control, we want to avoid including in
the email any user-controlled data. Doing so makes it hard for
malicious actors to use the feature to send spam, since they won't
have a way to include the URL for their malicious website in our
emails.
For almost all of these, the verbose support offer clause is almost the same
as the non-verbose version. The distinction carries extra carrying cost when
coming up with new copy, testing new email designs, etc.