As a co-founder, you accept the risk that if your company fails, you get nothing, and you might not get compensated for your time. That's just how startups work. High risk, high reward.
Therefore it's ridiculous to say OP deserves a % of revenue/profit/equity of their co-founders next venture. There's no legal or ethical basis for negotiating this.
But from the OP it sounds like the cofounder might be continuing in the same line of business, but wants to "pivot" and jettison the now-dead weight of the technologist.
If this is the case it seems plausible that his contributions and R&D are still relevant, even if they're throwing out his code, and so perhaps he's entitled to whatever stake he vested over those first two years.
This makes sense to me. If it's entirely unrelated then yeah totally. But if they're doing a shopify store to sell these workshops then I think OP should get some points
If the co-founder is taking any code, data, or customers to the next venture, then it seems fair the other co-founder should get something out of the new venture.
If the co-founder is taking just knowledge, best-practices, know-how, and life experience, then the other co-founder does not have any legal basis to expect anything.
Therefore it's ridiculous to say OP deserves a % of revenue/profit/equity of their co-founders next venture. There's no legal or ethical basis for negotiating this.