The STi and Evo VIII/IX models have definitely seemed to be a little slower to heat up, but there have been auction results for nice, lower mileage cars that indicate they are trending upward for sure. I wouldnt be surprised if it was included in future lists like these
The data set isn't meant to be utterly comprehensive. No question the MR2 is on people's radar, though, and you're right to ask about it. We included it in our 2019 Bull Market list:
https://www.hagerty.com/media/valuation/best-collector-cars-to-buy-now-2019-bull-market-list/
Most Allante owners are the only ones who care about them. They're so cheap that anyone who like them can afford them and already has one.