Below means nothing about how PD bring tracks to the game. Having a look at the European GT4 series. Last year's calendar had tracks featured in GTS: Monza, Brands Hatch and Nurburgring GP. This year https://european.gt4series.com/gb_en/calendar/13/2020 Silverstone replaces Brands Hatch and Monza is dropped for Spa. I can see Silverstone being the most realistic chance coming to GTS. The only "obscure" real world track in GTS, is Autopolis. I can't see Zandvoort or Budapest coming(I didn't see Autopolis coming either).