it was introduced in ff8651c4 to suppress deprecated
warnings for CALL under the flawed logic that "It's doesn't
make sense to print out deprecated syntax warnings when the
routine is being executed because this kind of warning only
matters when the routine is being created".

Which is incorrect, a feature might become deprecated after
the routine was created and a user has to know that to be able
to update the procedure before it stops working when a
deprecated feature is removed.