Edit: This was written before his release.
Before I begin, I do want to point out that as the title explains, I will only be using the information that we know at this point, which has been confirmed by the developers.
The big idea I want to focus on is balance, which is up in the air since one of Warly's only upsides was VERY vaguely mentioned. The crockpot speed doesn't really mean anything, and is a very minimal upside. I would have liked to see Warly's basic crockpot dishes get boosted stats right from the start, which would make him a good character for those people who like to sit in the base of big groups and just mass produce crockpot recipes. However I am willing to accept that it would be difficult to incorporate that, only if the spices make up for it. Those are Warly's only two upsides, 20% crockpot speed and the ability to add bonus effects to crockpot dishes. I'm not including his big boy tummy due to it still being worse than other survivors since he has the increased hunger drain.
Warly also has some NASTY downsides. They doubled down on the negative stats he had in singleplayer, which is what made everyone hate him. Not only that, but they removed the one upside that counteracted the downsides, which was that he gets bonus stats from crockpot dishes. I was surprised to see that upside wasn't directly mentioned in the announcement. Rather than getting bonus stats, they just made it so he can ONLY eat crockpot dishes. Hopefully with these really harsh downsides, his upsides balance things out.
With that in mind, it is important to remember that a lot of the cool stuff mentioned in the post is going to be available to all characters, not just him. Most of the new recipes and all the new vegetables are for everyone, not just Warly (even though he will get a lot more use out of them). Therefore they are not upsides, just cool content being added at the same time Warly is.
This brings me to my main point which is Warly's Famous Herbs and Spices. All we know about them is that he can attach bonus effects to any crockpot recipe. How good the effects will be is unknown, as well as what kind of effects they are, how difficult the spices will be to make, etc. This is what will make or break this character, and has so much potential. Honestly, I say to make this character viable, the spices need to be really powerful. A few scatterbrained Warly-themed forums posts ago, I mentioned that I want Warly to be a character that is taxing on the person playing as him, for a huge benefit to the rest of the team. As it stands, he has potential to be just that, a character who at his core is difficult to play, but a consistent source of really useful team based benefits. This can only be done if his main upside is powerful enough to make him worth playing for the sake of the team. Please don't make Warly's spices only give the relatively disappointing passive temperature effects of spicy chili, ice cream, or the effects from Hallowed Nights potions. He would be so much better with spices that temporarily add movement speed increase, damage increase, damage resistance, sanity gain, etc.
(Also just as a side thought, I think Warly's spices should not have "freshness" and should just last forever if not used. This is mainly because I like the idea of having a spice rack in the form of a chest without having to worry about those pesky expiration dates. Cut the guy some slack, he doesn't get to enjoy any of the holiday treats. At least let him have the ability to stockpile spices)