"She will be meeting George."
Translation:Bidh i a' coinneachadh ri Seòras.
That is quite correct. It depends on what sort of meeting it is, as clarified here.
But note the correct preposition is air not ri. But even that is not common. Much more common is to use the word as a noun - it can be both, just like the English word visit
|dèan cèilidh air||make a visit on||visit|
|cuir cèilidh air||put a visit on||visit|
|bi air cèilidh air||be on a visit on||be visiting|
|thig air cèilidh air||come on a visit on||come to visit|
|rach air cèilidh air||go on a visit on||go to visit|
No. There is nothing ambiguous. The point that they are making is that you have to know to put the word in in Gaelic even if it is not there in the English. If they put it in (which is actually more common in American English that the British English the course writers know) then you might think you could leave it out in Gaelic in the same way that you can leave it out in English. D