Although the block does not seem to be updated, which is a surprise considering the size of the TR4 socket and the Threadripper CPUs, Arctic Cooling Liquid Freezer AiO coolers will support it. Available in three versions, with 360mm, 240mm and 120mm radiators, all three use the same 12V pump and the same copper cold plate.
All three also use Arctic Cooling's F12 120mm fans in a push-pull configuration (two for 120mm version, four for 240mm and six for 360mm version). These spin between 500 and 1,350 RPM and produce 74 CFM of airflow at 0.3 Sone of noise.
According to Arctic Cooling, its Liquid Freezer 360 and Liquid Freezer 240 AiO coolers are capable of handling up to 350W TDP (up to 300W recommended), while the Liquid Freezer 120 can handle up to 300W TDP CPUs (up to 250W recommended), which should be enough for AMD's Threadripper CPUs.
In case you are wondering, these are also compatible with AMD AM4, FM2+, FM2, FM1, AM3+, AM3, AM2+ and AM2 sockets and Intel's LGA2011, LGA115X, LGA775/1366 sockets. The Arctic Cooling Liquid Freezer lineup is already available and priced at US $140 for the 360, US $100 for the 240 and US $86 for the Liquid Freezer 120 version, so we guess the price remains the same.