No idea, but I tried it, and he's right. With just a single TBM (no MediaVPs) allowing me to fly a Seraphim, I can see those descriptions. Who woulda' thought....
EDIT: Here's the relevant shp.tbm:
#Ship Classes
$Name: SB Seraphim
;; Note no descriptions here.
$Allowed PBanks: ( "Subach HL-7" )
$Default PBanks: ( "Subach HL-7" "Subach HL-7" "Subach HL-7" )
$Allowed SBanks: ( "Rockeye" "Tempest" )
$Default SBanks: ( "Tempest" "Tempest" "Rockeye" "Rockeye" )
$SBank Capacity: ( 40, 40, 80, 80 )
$Flags: ( "player_ship" "bomber" )
#End
EDIT2: I believe it's hard-coded. In missionshipchoice.cpp circa line 1070 you can find some of those strings.