The simplicity is obvious. (B.1.1.7s new name is Alpha.) Greek letters are often used as parts of scientific labels, which adds authority to the idea. The Greek-letter labelling proposed by the WHO is therefore an official attempt to provide the convenience of simple, uncontroversial monikers. These old names are not abandoned.
Video showed the kidnapping of a BROWNSVILLE person.
( z0 show :ARG0 ( z1 video ) :ARG1 ( z2 kidnap :ARG1 ( z3 person :location ( z4 city :name ( z5 name :op "Brisbane" ) ) ) ) )
(z0 / show-01
    :ARG0 (z1 / video)
    :ARG1 (z2 / kidnap-01
              :ARG1 (z3 / person
                        :location (z4 / city
                                      :name (z5 / name
                                                :op1 "Brisbane")))))
Video showed the kidnapping of a BROWNSVILLE person .
z0 :ARG0 z1
z0 :ARG1 z2
z4 :name z5
z5 :op1 0
z3 :location z4
z2 :ARG1 z3