It depends on the launch window of nextgen system. Nevertheless, it will launch in 2026 at least (there was information that it could already appear in 2026). Even if next xbox launches in 2026 the current XS has a couple of years to gain at least 10 miilion to the 40+ mil number. It's possible to do that. But in terms of reaching more units sold (50-60 mil) it might be difficult to do that. If nextgen Xbox launches in 2027-2028 it may reach 50+ mil. Xbox Series won't have a Pro Version like Xbox One had so it changes a lot of things includind the duration of its life cycle. Xbox Series may launch earlier without Pro Version.