A great feature needs great documentation. Please take a look!
very nit: I'd s/import/dllimport/. It's a bit longer, but not much, and more greppable. (for both + and - versions)
"to not be applied" sounds more correct to me, but I'm not a native speaker either. And I think "to not apply to inline member functions" works to and is shorter and not passive, and it makes the part after the comma sound better (with the passive I think it might have to be "as they otherwise would be"?)
Maybe suggest a workaround in addition to pointing out the problem? ("In these cases, a workaround is to make foo() not inline" or similar)