Meanwhile Thailand has come out to say they don't plan to open...

Meanwhile Thailand has come out to say they don't plan to open for tourism again until 2021, Vietnam is highly likely to be the same, and Cambodia may decide to reciprocate the same policies back to Thailand/VN - although they really do need the tourist dollars so perhaps not.

My curiosities are; will Thai citizens who enter Cambodia and then try to return home be quarantined? If so, they won't be visiting.
What will happen if S.V is open to tourists, and then a guest tests positive? It's likely to be shutdown, disinfected, all guests and visitors tracked down and put into mandatory quarantine and not allowed to reopen for some time. Honestly it seems almost inevitable for that to happen.