Risk production doesn't mean devices showing up at retail. But their claimed roadmap is consistent with 5 nm devices showing up at retail in 2020 and 3 nm in 2021.
Part of the cause is surely inflated marketing names for the process nodes. If you were to take the main specs of Samsung's 7 nm process node and TSMC's 7 nm process node back in time ten years and ask someone knowledgeable about this sort of thing what process node size they were for, the answer would probably be 11 nm. The specs are close to Intel's 10 nm node, for that matter. So it's likely that the "3 nm" name is partially a case of getting further away from how nodes would have traditionally been named.
EUV will certainly help, and it might well help a lot. Everyone seems to think that 7 nm is when EUV finally gets used after so many years of delay. But the whole history of process node advances is a long chain of improvements of one type or another, from copper interconnects to silicon on insulator to high-k metal gates to FinFETs, so it's not like EUV is the only thing that has ever made more advanced process nodes available.
You can bet that the upcoming Samsung process nodes will be used for cell phone chips. Less clear is whether they'll be used for the CPUs and GPUs that power our PCs. Nvidia has gone with TSMC since just about forever, and AMD has had most of their GPUs and a handful of CPUs fabricated at TSMC, too. You could argue that AMD's 14 nm CPUs and GPUs were basically Samsung's process node, since that's where Global Foundries licensed it from. But it's not clear whether AMD was happy with the process node or merely stuck with it due to their wafer sharing agreement with Global Foundries.