The original game, if I remember correctly, replaces the postview screen altogether.
NeoLemmix also has no concept of an "end of pack" message as such; only an "end of level" message. In most use cases where it matters (which are a minority in the first place, I'd believe), it would make more sense to have the postview text before the postview screen rather than after it; though I certainly don't feel strongly enough about this to say "this cannot change" (aside from technical considerations, where the much easier option is "leave it as is").