All your existing V-wings are updated to the new, higher mark. The cap used to increase a lot with each upgrade as well, just like classic, but the rate of increase was scaled back in a recent-ish patch as part of an effort to address some severe balance issues with the power scaling of high tier units (Basically, the power level was increasing quadratically compared to the research cost). The caps for fleetships were also always lower in AIW2, since each unit is a squad rather than a single unit, but, AFIK with the intention that since the cap strength is balanced similarly, the lower cap doesn't really matter, since we would never use fleetships in quantities below dozens at the absolute minimum in classic anyway.