I think there's a risk here but I'm not sure it goes as far as you suggest. There are still plenty of entities, particularly larger ones, that buy their own metal because at some scales it becomes far cheaper to run in a COLO (at least acc to near monthly articles posted on HN). I'd therefore put the risk that only big vendors will be able to buy hardware as low. That said, as ARM or custom chips gain market share within cloud providers, there's a risk that x86 or standard suppliers will struggle, but AMD/Intel see this too and surely one or both will adapt.
On skills I think there's a small risk of people not knowing how to manage/set up their own racks, but doing a passable job there isn't that hard. On general sys-admin stuff, cloud infrastructure seems to have parallels to hardware infrastructure, so it shouldn't be completely unfamiliar to set up a hardware router/network/linux server. There are definitely skills and details missing (remote admin tools for hardware maybe), but this doesn't seem like a big gap to bridge if $$$ is on the line?
On skills I think there's a small risk of people not knowing how to manage/set up their own racks, but doing a passable job there isn't that hard. On general sys-admin stuff, cloud infrastructure seems to have parallels to hardware infrastructure, so it shouldn't be completely unfamiliar to set up a hardware router/network/linux server. There are definitely skills and details missing (remote admin tools for hardware maybe), but this doesn't seem like a big gap to bridge if $$$ is on the line?