ah, we must be talking about two different lists then. The list I was thinking of was very early on. Lips, Annie Sue, Thog, etc didn't come up in discussion until much later on when they knew they were going beyond 4 waves.
Well I think we are thinking of the same lists. It's hard to find it using the internet wayback machine (I can find older versions of Muppet central, but the delphi forum still doesn't seem to come up). I know that Tough Pigs included that list, along with other info that came from the posts. It seems like this Palisades news was eventually taken down from the site.
And I'm not too sure whether Annie Sue or Thog were listed (I am more sure about Thog), but I'm sure Lips was in that list, even though several months later Ken said he asked about Lips and Henson wasn't too sold on the idea. i recaall Lips being there because he was one of the top five characters I wanted most and was excitted to see him listed.
Of course that list was a bit odd. Ken said he wanted each series to have two big guns, a secondary, and a fan fave, but the secondary list had both Dr. Teeth and Bunsen listed (I figured Dr. Teeth was the secondary in this case, before realising the lsit was from Muppet Show standards). But I think series 2 and 3 were really the only ones to follow the rule based on that list (thought he originally announced series 4 line-up - with a TBD Kermit variant, Sam, Dr. Strangepork, and Janice- did follow that pattern).
I think that deep down the people at Palisades did plan on more than four. When series four was announced, Link (with Pigs in Space playset) and Dr. Strangepork were announced, but there was no First Mate Piggy announced for series four. And a Gonzo variant was released before a regular Gonzo, which didn't come out until series 5.
Still, that list had some choices that I foudn odd. I thought it was weird that Beaker and Sam were listed as big guns, sicne those two were hardly ever made as merchandise (Beaker merchandise had just started being made two years prior to that). I was more surprised, though, that Bunsen and Beaker were categorized differently. I also found it odd that Link Hogthrob and Robin were listed as fan faves instead of secodnary.