The sentence begins with “if”, because I wasn’t - and am not - following your logic.
Yes, those who buy Cubase buy a license technically, and that license is platform agnostic.
But you imply that offering Linux would increase revenue, and that would mean gaining new users, not the ones that already bought Cubase for other platforms. So the distinction is essentially irrelevant unless you’re trying to say there is no difference in revenue because all that would happen is that users would move over from Win/OSX to Linux.
So again, the question is how many people there are out there that want to use Cubase but are not going to spend money on it because it isn’t on Linux, but if it became available for Linux then would buy the license. Every user that has already bought a license or are going to buy a license without Cubase running on Linux are irrelevant to conversation of increasing profit, or at the very least paying for increased expenses.
See my point?