I remember the Playstation gamees where they were in CGI.
It didn't look good.
But people shouldn't worry about that, since they will never make a CGI Rugrats movie, or another movie of them at all, until maybe 20 years from now where they try to revive old franchises.
From the shots I've seen, the CGI looks pretty bad, I mean DTV, or Reboot Season 1 bad.
But hopefully it's too early to tell.