But it doesn't affect you playing the rest of the series. So what if they skipped a number? I don't see how that will affect you playing the earlier and later games...

And Ouch! hit it on the nail, it's such an overused arguement. It get's a bit annoying.

Edit: I can strongly say this game isn't going to end in 5 years. Hardly many mainstream MMORPG's end, some are still going strong from a decade ago.