Was it a thing where stations had to take all three shows, or did some affiliates take only one or two? I do remember visiting Dallas in the summer of '90, and seeing Talk About around 10:30 am; I believe the other two were canceled by that point.
The Fox O&O's and some Fox affiliates (such as WTVZ) picked up all three but it was never a formal block as they were all under different syndicators. Some had them split between stations (Seattle), some missed a show (Philly had no
Talk About), some carried only one show (e.g. Raleigh/Durham and Portland, ME only had
Jackpot!).
In the Detroit market, we got Talkabout from CBC Windsor, so we got a couple of years of it that American viewers never saw.
I wonder if this played a role in WXON (or anyone else) passing on the show even though they were able to. I can't find Buffalo listings for 1989 so I can't see if they acted similarly, other markets serving cities in Canada were too small or far from the border for this to matter. In Seattle
Talk About was on KTZZ, the only commercial station without carriage in Canada (the other two were on KCPQ which did and does).