No, Squeek's Oddysee was merely, as Xavier said, the first character he used to convince Sherry McKenna to fund Oddworld Inhabitants. Unless you can provide the interview or article in which he says this, which I have always been intrigued about, I'm going to have to take it as a misunderstanding somewhere along the line. Now I'm dreading my next paragraph, because it makes me the biggest hypocrite the Forums have ever seen.
I've never heard of 'Forte' either. However, I have heard of 'Nod', the fourth hero. I don't have evidence, though, as the Inhabitants Interview in which he was mentioned has long been lost. A few other fans could back me up, but I'm positive most, if not all of them are no longer interested in Oddworld, and are certainly not frequenters of the Forums anymore. Forte is an interesting name, though, especially since it contains the syllable 'four'.
And Squeek was Sherry McKenna's favourite character... until she was won over with Abe.
EDIT: In my excitement, I missed a couple of points. The first was simply that even if Lorne had originally intended Squeek to come first, Abe is first now, and it's the Quintology now we still follow. What's more, character design isn't determined until the game is under production - thoughts were put into making Munch a flying creature, for instance. It makes you wonder what precisely Lorne's original ideas were. However, what you say about putting Abe first to have audiences hooked on a more humanoid character does ring a very quiet bell. Maybe it wasn't so much a humanoid character as a very human-based situation. Not many of people have had their species hunted to near extinction, for example, so the empathy just gets lost.
I'd investigate more, I really would, but I don't have any time at all.
The other point goes back to Oddworld blurring the lines between good and bad. Clearly chopping up your workers is a bad thing to do, and it's silly saying that Oddworld wanted to justify that - but the needs and nurturing of all characters bears through their actions. If what I posted in the other topic about Khanzumerz being the true evil is accurate, then Glukkons are under even more pressure than we thought. These pressures have been exentuated (sp) over literally hundreds of years on Oddworld. It's important to remember two things also:
1) Oddworld Inhabitants are highly resiliant to change. That's not to say they cope with it well, that's to say they don't do it very much. The ideologies of the native races of Oddworld are simply not programmed into Glukkon minds, and it's not fair to assume they can change their minds at all, because...
2) Oddworld characters are certainly not humans with exagerated personalities. The Glukkon mind works very differently to ours. Fresh ideas, when presented to them, like eco-friendliness and worker rights, cannot worm into their conscience, because their minds don't work like that at all. This makes their opinion of themselves not being evil all the more justified.
With Glukkons and Vykkers, it's not a case of having an outlook on life that's very wrong, but which they consider good. One character's experiences are irrelevant at this point. What the Quintology shows are entire species who very basic and instinctive natures demand certain things from them: eg a subconscious desire to be at high altitudes, or a subtle but fundamental hatred of Mudokons. It's not quite the case of the regular Evil Genius with a traumatic childhood.
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And as Xavier said, Squeek was merely the first character he pitched to Sherry in a bid to win her over 
Squeek was also Lorne's favourite.