Tour Down Under has been on various European networks, including occasionally on ES. Pologne was on ES as recently as 2020 and on l'Equipe last year.
Just a guess but my impression is that the broadcasting landscape has changed over the last couple of years with the shift towards specialist subscription platforms. Deals are made with the bigger organizers (ASO, RCS, Flanders Classics) or with packages for smaller races (e.g., French Cup , Belgian Cup) and it's a little more complicated for the one-off WT races.
Tour de Suisse wasn't broadcast on GCN in my region, either. It was on some network I never heard off. Luckily, I could watch because it was on l'Equipe (geo-restricted) and then archived on Yahoo Sport France (non-restricted).