Bear in mind the 16 weight classes are merged into 8 at the Olympics; barring a disaster, Jones (-57kg) and Walkden (+67kg) look to be assured of selection for Rio.
I may have said the same about Cho (+80kg), but Samsun is doing -87kg at the ECh - I don't know what to make of that as he's an -80kg competitor like Muhammad AFAIK.
This article suggests the latter two are still battling each other for Olympic -80kg selection, anyhow.
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In Mexico, it's gold for defending champion Nick Thompson at the Laser World Championships! All-in-all, three British sailors will compete in Rio as world champions* (plus a few medallists), so the squad is in a very good place.
[* All on one-man dinghies, for what that's worth]