Thresh transcends the so-called "metas" that bind other champion's usefulness.
Although it does really suck that certain mage supports are becoming more popular as time goes on. Thresh really doesn't have very many good engagement opportunities against Brand and Velkoz (other than landing your Q and your ADC seizing the opportunity, but that is dependant on what your ADC can accomplish with the given time), ugh....
Oh no, the support with the overloaded kit is getting some harder matchups...
Most of them are more than 800 range indeed.
Some champions that have 800 or more AOE skillshots:
Xerath, Lux, Ahri, Varus, Corki, Karma, Soraka, Heimerdinger, Syndra (her Q is exactly 800), Sejuani,