Looks like this poll was somehow conducted today (Jan. 4th), so at least some of the respondents presumably would've heard about Trump's call with Raffensperger.
Maybe they just listed the date of publication? I don't know how they could possibly think they got a representative sample if they only asked people who answer the phone before noon (accounting for a few hours needed to weight, put together a press release, etc.) on a single day.
The poll was conducted January 3.
The final InsiderAdvantage/Fox 5 Atlanta poll ahead of tomorrow’s U.S. Senate runoffs shows a pair of deadlocked races. The poll was conducted January 3rd and surveyed 500 likely voters with a margin of error of 4.4 percent. Crosstabs can be found HERE